Cu₃Sn – understanding the systematic absences

The intermetallic compound Cu₃Sn has previously been described as a long-period antiphase boundary superstructure of the Cu₃Ti structure type. While the compound itself has been reported as a tenfold and an eightfold superstructure, ternary doped alloys show shorter repetitions. Interestingly, the diffraction patterns of these compounds show non-crystallographic absences that cannot be explained using the superstructure models. Since the compound exhibits phase broadening, these models are not satisfactory because the paucity of observed data does not allow for a refinement of the composition. Here, an alternative, superspace model in the orthorhombic space group Xmcm(0β0)000 is proposed, with the centering vectors (0,0,0,0) and (½,0,0,½). The presence of the non-crystallographic absences is explained as a result of a dominating occupational modulation that is accompanied by a weaker displacive modulation. In consistency with the EDXS results, the composition has been refined to Cu_3 + xSn from single-crystal X-ray diffraction data. It is further demonstrated that by varying the length and the direction of the modulation wavevector in the superspace model, the ternary Cu₃Sn compounds and other colored hexagonal close packing (h.c.p.) structures can be produced.

Computing details

Data collection: CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) for 473K-superstructure, 573K-superstructure, 673K-superstructure, 723K-superstructure, 823K-superstructure, 673K-modulated; CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) for 473K-modulated, 573K-modulated, 723K-modulated, 823K-modulated. Cell refinement: CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) for 473K-superstructure, 573K-superstructure, 673K-superstructure, 723K-superstructure, 823K-superstructure, 673K-modulated; CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) for 473K-modulated, 573K-modulated, 723K-modulated, 823K-modulated. Data reduction: CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) for 473K-superstructure, 573K-superstructure, 673K-superstructure, 723K-superstructure, 823K-superstructure, 673K-modulated; CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) for 473K-modulated, 573K-modulated, 723K-modulated, 823K-modulated.

Figures

(473K-superstructure)

Crystal data

Cu3Sn	F(000) = 2740
Mr = 309.3	Dx = 8.983 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -C -2x;-2yc;-2zc	Cell parameters from 780 reflections
a = 5.5210 (2) Å	θ = 3.4–28.4°
b = 47.781 (3) Å	µ = 37.87 mm^−1
c = 4.3340 (2) Å	T = 293 K
V = 1143.30 (10) Å^3	Trigonal prismatic, metallic grey
Z = 20	0.06 × 0.02 × 0.02 mm

Data collection

Xcalibur, Eos diffractometer	851 independent reflections
Radiation source: Enhance (Mo) X-ray Source	332 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.032
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.4°, θmin = 3.4°
ω scans	h = −7→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −61→62
Tmin = 0.372, Tmax = 0.7	l = −5→5
5911 measured reflections

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.038	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0035999999I^2)
wR(F^2) = 0.172	(Δ/σ)max = 0.040
S = 1.17	Δρmax = 2.22 e Å^−3
851 reflections	Δρmin = −2.36 e Å^−3
72 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 43 (13)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0	0.33365 (4)	0.25	0.0061 (6)
Sn2	0.5	0.36610 (4)	−0.25	0.0074 (6)
Sn3	0.5	0.26620 (4)	−0.25	0.0043 (5)
Cu1	0.2480 (3)	0.38408 (7)	0.25	0.0124 (11)
Cu2	0.2402 (3)	0.48427 (7)	−0.75	0.0108 (10)
Cu3	0.2521 (3)	0.41582 (7)	−0.25	0.0135 (11)
Cu4	0.2526 (3)	0.31614 (6)	−0.25	0.0065 (10)
Cu5	0.2485 (3)	0.28401 (6)	0.25	0.0066 (10)
Sn4	0.5	0.46640 (4)	−0.25	0.0081 (6)
Sn5	0	0.43334 (4)	−0.75	0.0089 (7)
Cu6	0.5	0.43178 (7)	−0.75	0.0079 (11)
Cu7	0	0.46921 (7)	−1.25	0.0057 (10)
Cu8	0	0.36961 (7)	−0.25	0.0103 (11)
Cu9	0	0.26929 (8)	−0.25	0.0089 (11)
Cu10	−0.5	0.33070 (7)	0.25	0.0078 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0046 (10)	0.0066 (9)	0.0072 (12)	0	0	0
Sn2	0.0076 (11)	0.0069 (9)	0.0077 (13)	0	0	0
Sn3	0.0046 (10)	0.0050 (8)	0.0032 (11)	0	0	0
Cu1	0.016 (2)	0.0143 (16)	0.007 (2)	0.0005 (7)	0	0
Cu2	0.0104 (17)	0.0128 (14)	0.009 (2)	−0.0015 (6)	0	0
Cu3	0.0142 (19)	0.0114 (16)	0.015 (2)	−0.0011 (7)	0	0
Cu4	0.0049 (16)	0.0087 (14)	0.006 (2)	−0.0016 (6)	0	0
Cu5	0.0112 (18)	0.0008 (12)	0.008 (2)	0.0002 (5)	0	0
Sn4	0.0078 (11)	0.0089 (9)	0.0077 (12)	0	0	0
Sn5	0.0092 (11)	0.0082 (9)	0.0092 (13)	0	0	0
Cu6	0.0038 (18)	0.0155 (17)	0.004 (2)	0	0	0
Cu7	0.0036 (18)	0.0094 (16)	0.004 (2)	0	0	0
Cu8	0.010 (2)	0.0091 (16)	0.011 (2)	0	0	0
Cu9	0.0075 (18)	0.0124 (15)	0.007 (2)	0	0	0
Cu10	0.0037 (17)	0.0121 (16)	0.008 (2)	0	0	0

Bond lengths (Å)

Sn1—Sn1^i	5.5210 (4)	Cu2—Cu3^xxix	5.536 (4)
Sn1—Sn1^ii	4.3340 (4)	Cu2—Cu3^xxxii	4.773 (3)
Sn1—Sn1^iii	4.3340 (4)	Cu2—Cu3^vii	4.773 (3)
Sn1—Sn1^iv	5.5210 (4)	Cu2—Cu3^xv	4.821 (3)
Sn1—Sn2^i	3.8367 (11)	Cu2—Cu3^xi	4.821 (3)
Sn1—Sn2^v	3.8367 (11)	Cu2—Cu3^xxxv	4.774 (5)
Sn1—Sn2	3.8370 (11)	Cu2—Sn4^xxxvi	4.7040 (17)
Sn1—Sn2^iii	3.8369 (11)	Cu2—Sn4^i	4.7040 (17)
Sn1—Sn3^i	4.7647 (18)	Cu2—Sn4^ii	2.7352 (15)
Sn1—Sn3^v	4.7648 (18)	Cu2—Sn4	2.7353 (15)
Sn1—Sn3	4.7643 (18)	Cu2—Sn4^xxvii	4.718 (2)
Sn1—Sn3^iii	4.7644 (18)	Cu2—Sn4^xxxvii	5.1379 (19)
Sn1—Sn3^vi	4.771 (3)	Cu2—Sn4^xxix	2.759 (3)
Sn1—Cu1^i	4.800 (2)	Cu2—Sn4^xxx	5.1378 (19)
Sn1—Cu1^ii	5.1444 (19)	Cu2—Sn5^ii	5.1444 (19)
Sn1—Cu1	2.771 (3)	Cu2—Sn5	2.772 (3)
Sn1—Cu1^iii	5.1443 (19)	Cu2—Sn5^iii	5.1445 (19)
Sn1—Cu1^vii	5.1443 (19)	Cu2—Sn5^iv	4.849 (2)
Sn1—Cu1^viii	2.771 (3)	Cu2—Sn5^xxvii	4.685 (3)
Sn1—Cu1^ix	5.1442 (19)	Cu2—Sn5^xxviii	4.685 (3)
Sn1—Cu1^x	4.801 (2)	Cu2—Cu6^i	4.795 (3)
Sn1—Cu3	4.696 (3)	Cu2—Cu6^ii	5.209 (2)
Sn1—Cu3^iii	4.696 (3)	Cu2—Cu6	2.889 (4)
Sn1—Cu3^vii	4.696 (3)	Cu2—Cu6^iii	5.209 (2)
Sn1—Cu3^viii	4.695 (3)	Cu2—Cu6^xxix	4.780 (4)
Sn1—Cu4^i	4.7355 (15)	Cu2—Cu6^xxx	4.779 (4)
Sn1—Cu4^v	4.7355 (15)	Cu2—Cu7	2.6407 (15)
Sn1—Cu4	2.7091 (13)	Cu2—Cu7^iii	2.6407 (15)
Sn1—Cu4^iii	2.7092 (13)	Cu2—Cu7^iv	4.7758 (17)
Sn1—Cu4^vii	2.7092 (13)	Cu2—Cu7^xiv	4.7759 (17)
Sn1—Cu4^viii	2.7093 (13)	Cu2—Cu7^xxvii	5.048 (2)
Sn1—Cu4^xi	4.7353 (15)	Cu2—Cu7^xxviii	2.588 (4)
Sn1—Cu4^x	4.7353 (15)	Cu2—Cu7^xxxviii	5.048 (2)
Sn1—Cu5^i	4.779 (2)	Cu2—Cu7^xxx	4.748 (3)
Sn1—Cu5^ii	5.1274 (16)	Cu3—Cu3^i	5.521 (2)
Sn1—Cu5	2.740 (3)	Cu3—Cu3^ii	4.3340 (4)
Sn1—Cu5^iii	5.1276 (16)	Cu3—Cu3^iii	4.3340 (4)
Sn1—Cu5^vii	5.1276 (16)	Cu3—Cu3^iv	5.521 (2)
Sn1—Cu5^viii	2.740 (3)	Cu3—Cu3^xxxii	5.1511 (13)
Sn1—Cu5^ix	5.1277 (16)	Cu3—Cu3^vii	2.784 (2)
Sn1—Cu5^x	4.779 (2)	Cu3—Cu3^viii	5.1511 (13)
Sn1—Sn5^iii	4.763 (3)	Cu3—Cu3^xv	5.1259 (13)
Sn1—Cu6^v	5.441 (3)	Cu3—Cu3^xi	2.737 (2)
Sn1—Cu6^iii	5.441 (3)	Cu3—Cu3^x	5.1259 (13)
Sn1—Cu8	2.765 (2)	Cu3—Cu4	4.763 (4)
Sn1—Cu8^iii	2.765 (2)	Cu3—Cu4^vii	5.518 (4)
Sn1—Cu9	3.762 (3)	Cu3—Cu4^xi	5.492 (4)
Sn1—Cu9^iii	3.762 (3)	Cu3—Sn4^i	4.804 (2)
Sn1—Cu9^xii	5.640 (4)	Cu3—Sn4^ii	5.1476 (18)
Sn1—Cu9^vi	5.640 (4)	Cu3—Sn4	2.777 (3)
Sn1—Cu10^ii	5.1404 (4)	Cu3—Sn4^iii	5.1475 (18)
Sn1—Cu10	2.7641 (3)	Cu3—Sn5	2.7081 (14)
Sn1—Cu10^iii	5.1404 (4)	Cu3—Sn5^iii	2.7081 (14)
Sn1—Cu10^xiii	5.1404 (4)	Cu3—Sn5^iv	4.7378 (16)
Sn1—Cu10^iv	2.7641 (3)	Cu3—Sn5^xiv	4.7377 (16)
Sn1—Cu10^xiv	5.1404 (4)	Cu3—Cu6^i	4.7455 (16)
Sn2—Sn2^i	5.5210 (4)	Cu3—Cu6^v	4.7455 (16)
Sn2—Sn2^ii	4.3340 (4)	Cu3—Cu6	2.6741 (16)
Sn2—Sn2^iii	4.3340 (4)	Cu3—Cu6^iii	2.6740 (16)
Sn2—Sn2^iv	5.5210 (4)	Cu3—Cu7	5.218 (2)
Sn2—Sn3	4.773 (3)	Cu3—Cu7^iii	2.906 (4)
Sn2—Cu1^ii	2.7146 (15)	Cu3—Cu7^xxvi	5.218 (2)
Sn2—Cu1	2.7146 (15)	Cu3—Cu7^xiv	4.854 (3)
Sn2—Cu1^xiii	4.7421 (16)	Cu3—Cu8^ii	5.059 (2)
Sn2—Cu1^iv	4.7421 (16)	Cu3—Cu8	2.610 (4)
Sn2—Cu1^vii	4.7420 (16)	Cu3—Cu8^iii	5.059 (2)
Sn2—Cu1^viii	4.7420 (16)	Cu3—Cu8^iv	4.682 (3)
Sn2—Cu1^xi	2.7147 (15)	Cu3—Cu10^xiii	4.807 (4)
Sn2—Cu1^x	2.7147 (15)	Cu3—Cu10^iv	4.807 (4)
Sn2—Cu3^ii	5.1283 (18)	Cu4—Cu4^i	5.521 (2)
Sn2—Cu3	2.741 (3)	Cu4—Cu4^ii	4.3340 (4)
Sn2—Cu3^iii	5.1281 (18)	Cu4—Cu4^iii	4.3340 (4)
Sn2—Cu3^iv	4.784 (2)	Cu4—Cu4^iv	5.521 (2)
Sn2—Cu3^vii	4.784 (2)	Cu4—Cu4^xxxii	5.1537 (12)
Sn2—Cu3^xv	5.1284 (18)	Cu4—Cu4^vii	2.789 (2)
Sn2—Cu3^xi	2.742 (3)	Cu4—Cu4^viii	5.1537 (12)
Sn2—Cu3^x	5.1283 (18)	Cu4—Cu4^xv	5.1233 (12)
Sn2—Cu4^ii	5.1330 (17)	Cu4—Cu4^xi	2.732 (2)
Sn2—Cu4	2.750 (3)	Cu4—Cu4^x	5.1233 (12)
Sn2—Cu4^iii	5.1332 (17)	Cu4—Cu5^ii	2.656 (2)
Sn2—Cu4^iv	4.792 (2)	Cu4—Cu5	2.656 (2)
Sn2—Cu4^vii	4.792 (2)	Cu4—Cu5^xvi	4.786 (4)
Sn2—Cu4^xv	5.1329 (17)	Cu4—Cu5^vii	3.835 (2)
Sn2—Cu4^xi	2.750 (3)	Cu4—Cu5^viii	3.835 (2)
Sn2—Cu4^x	5.1330 (17)	Cu4—Cu5^xi	3.826 (2)
Sn2—Cu5^ii	4.691 (3)	Cu4—Cu5^x	3.826 (2)
Sn2—Cu5	4.692 (3)	Cu4—Cu5^xxii	5.536 (4)
Sn2—Cu5^xi	4.691 (3)	Cu4—Cu5^xx	5.513 (4)
Sn2—Cu5^x	4.691 (3)	Cu4—Cu8^ii	5.220 (2)
Sn2—Sn4	4.792 (3)	Cu4—Cu8	2.910 (4)
Sn2—Sn5	4.7576 (18)	Cu4—Cu8^iii	5.220 (2)
Sn2—Sn5^iii	4.7575 (18)	Cu4—Cu8^iv	4.853 (3)
Sn2—Sn5^iv	4.7580 (18)	Cu4—Cu9^ii	5.074 (2)
Sn2—Sn5^xiv	4.7579 (18)	Cu4—Cu9	2.638 (4)
Sn2—Cu6	3.814 (3)	Cu4—Cu9^iii	5.074 (2)
Sn2—Cu6^iii	3.814 (3)	Cu4—Cu9^iv	4.695 (3)
Sn2—Cu7^iii	5.647 (3)	Cu4—Cu9^xvi	4.819 (4)
Sn2—Cu7^xiv	5.647 (3)	Cu4—Cu9^vi	4.819 (4)
Sn2—Cu8^ii	5.1412 (4)	Cu4—Cu10^ii	4.7373 (15)
Sn2—Cu8	2.7655 (3)	Cu4—Cu10	4.7373 (15)
Sn2—Cu8^iii	5.1412 (4)	Cu4—Cu10^xiii	2.6544 (14)
Sn2—Cu8^xiii	5.1412 (4)	Cu4—Cu10^iv	2.6544 (14)
Sn2—Cu8^iv	2.7656 (3)	Cu5—Cu5^i	5.521 (2)
Sn2—Cu8^xiv	5.1412 (4)	Cu5—Cu5^ii	4.3340 (4)
Sn2—Cu9	5.387 (4)	Cu5—Cu5^iii	4.3340 (4)
Sn2—Cu9^iv	5.387 (4)	Cu5—Cu5^iv	5.521 (2)
Sn2—Cu10^xiii	2.749 (2)	Cu5—Cu5^xvi	3.906 (3)
Sn2—Cu10^iv	2.749 (2)	Cu5—Cu5^vi	3.906 (3)
Sn3—Sn3^i	5.5210 (4)	Cu5—Cu5^vii	5.1299 (12)
Sn3—Sn3^ii	4.3340 (4)	Cu5—Cu5^viii	2.745 (2)
Sn3—Sn3^iii	4.3340 (4)	Cu5—Cu5^ix	5.1299 (12)
Sn3—Sn3^iv	5.5210 (4)	Cu5—Cu5^xi	5.1471 (13)
Sn3—Sn3^xvi	3.8360 (11)	Cu5—Cu5^x	2.776 (2)
Sn3—Sn3^vi	3.8360 (11)	Cu5—Cu5^xxv	5.1471 (13)
Sn3—Sn3^xvii	3.8357 (11)	Cu5—Cu5^xxii	4.783 (3)
Sn3—Sn3^xviii	3.8358 (11)	Cu5—Cu5^xxxix	4.784 (3)
Sn3—Cu4^ii	5.1327 (17)	Cu5—Cu5^xx	4.783 (3)
Sn3—Cu4	2.750 (3)	Cu5—Cu5^xxiii	4.783 (3)
Sn3—Cu4^iii	5.1325 (17)	Cu5—Cu8	4.828 (4)
Sn3—Cu4^iv	4.792 (2)	Cu5—Cu8^iii	4.827 (4)
Sn3—Cu4^xvi	4.704 (3)	Cu5—Cu9	2.6597 (15)
Sn3—Cu4^vi	4.704 (3)	Cu5—Cu9^iii	2.6598 (15)
Sn3—Cu4^vii	4.791 (2)	Cu5—Cu9^iv	4.7331 (16)
Sn3—Cu4^xv	5.1328 (17)	Cu5—Cu9^xiv	4.7331 (16)
Sn3—Cu4^xi	2.750 (3)	Cu5—Cu9^xii	4.855 (3)
Sn3—Cu4^x	5.1326 (17)	Cu5—Cu9^xvi	5.215 (2)
Sn3—Cu4^xix	4.703 (3)	Cu5—Cu9^vi	2.900 (4)
Sn3—Cu4^xx	4.703 (3)	Cu5—Cu9^xl	5.215 (2)
Sn3—Cu5^ii	2.7105 (13)	Cu5—Cu10	4.696 (3)
Sn3—Cu5	2.7105 (13)	Cu5—Cu10^xiii	5.068 (2)
Sn3—Cu5^xiii	4.7435 (15)	Cu5—Cu10^iv	2.628 (4)
Sn3—Cu5^iv	4.7434 (15)	Cu5—Cu10^xiv	5.068 (2)
Sn3—Cu5^xxi	5.1404 (17)	Sn4—Sn4^i	5.5210 (4)
Sn3—Cu5^xvi	2.764 (3)	Sn4—Sn4^ii	4.3340 (4)
Sn3—Cu5^vi	5.1405 (17)	Sn4—Sn4^iii	4.3340 (4)
Sn3—Cu5^xvii	4.792 (2)	Sn4—Sn4^iv	5.5210 (4)
Sn3—Cu5^vii	4.7433 (15)	Sn4—Sn4^xxix	3.874 (2)
Sn3—Cu5^viii	4.7433 (15)	Sn4—Sn4^xxx	3.874 (2)
Sn3—Cu5^xi	2.7106 (13)	Sn4—Sn5	3.8486 (11)
Sn3—Cu5^x	2.7106 (13)	Sn4—Sn5^iii	3.8487 (11)
Sn3—Cu5^xxii	4.793 (2)	Sn4—Sn5^iv	3.8484 (11)
Sn3—Cu5^xix	5.1402 (17)	Sn4—Sn5^xiv	3.8485 (11)
Sn3—Cu5^xx	2.764 (3)	Sn4—Sn5^xxviii	5.529 (2)
Sn3—Cu5^xxiii	5.1404 (17)	Sn4—Sn5^xxx	5.529 (2)
Sn3—Cu8	5.659 (3)	Sn4—Cu6	2.726 (2)
Sn3—Cu8^iv	5.660 (3)	Sn4—Cu6^iii	2.726 (2)
Sn3—Cu9^ii	5.1406 (4)	Sn4—Cu6^xxx	4.865 (4)
Sn3—Cu9	2.7644 (3)	Sn4—Cu7	5.1402 (4)
Sn3—Cu9^iii	5.1406 (4)	Sn4—Cu7^iii	2.7637 (3)
Sn3—Cu9^xiii	5.1406 (4)	Sn4—Cu7^xxvi	5.1402 (4)
Sn3—Cu9^iv	2.7644 (3)	Sn4—Cu7^iv	5.1402 (4)
Sn3—Cu9^xiv	5.1406 (4)	Sn4—Cu7^xiv	2.7638 (3)
Sn3—Cu9^xvi	2.752 (3)	Sn4—Cu7^xli	5.1402 (4)
Sn3—Cu9^vi	2.752 (3)	Sn4—Cu7^xxviii	4.667 (2)
Sn3—Cu10^xiii	3.767 (3)	Sn4—Cu7^xxxviii	4.667 (2)
Sn3—Cu10^iv	3.767 (3)	Sn4—Cu7^xxx	4.668 (2)
Sn3—Cu10^xxiv	5.391 (3)	Sn4—Cu7^xlii	4.667 (2)
Sn3—Cu10^xvi	5.390 (3)	Sn4—Cu8	5.386 (3)
Cu1—Cu1^i	5.521 (2)	Sn4—Cu8^iv	5.386 (3)
Cu1—Cu1^ii	4.3340 (4)	Sn5—Sn5^i	5.5210 (4)
Cu1—Cu1^iii	4.3340 (4)	Sn5—Sn5^ii	4.3340 (4)
Cu1—Cu1^iv	5.521 (2)	Sn5—Sn5^iii	4.3340 (4)
Cu1—Cu1^vii	5.1265 (13)	Sn5—Sn5^iv	5.5210 (4)
Cu1—Cu1^viii	2.738 (2)	Sn5—Cu6^xxxvi	5.1390 (4)
Cu1—Cu1^ix	5.1265 (13)	Sn5—Cu6^i	2.7615 (2)
Cu1—Cu1^xi	5.1505 (13)	Sn5—Cu6^v	5.1390 (4)
Cu1—Cu1^x	2.783 (2)	Sn5—Cu6^ii	5.1390 (4)
Cu1—Cu1^xxv	5.1505 (13)	Sn5—Cu6	2.7615 (2)
Cu1—Cu2^iii	4.787 (5)	Sn5—Cu6^iii	5.1390 (4)
Cu1—Cu2^vii	5.494 (4)	Sn5—Cu7	2.763 (2)
Cu1—Cu2^xi	5.559 (4)	Sn5—Cu7^iii	2.763 (2)
Cu1—Cu3	2.645 (3)	Sn5—Cu7^xxviii	4.656 (4)
Cu1—Cu3^iii	2.645 (3)	Sn5—Cu8^ii	3.737 (3)
Cu1—Cu3^vii	3.823 (2)	Sn5—Cu8	3.738 (3)
Cu1—Cu3^viii	3.823 (2)	Sn5—Cu10^ii	5.628 (3)
Cu1—Cu3^xi	3.823 (2)	Sn5—Cu10^xiii	5.628 (3)
Cu1—Cu3^x	3.823 (2)	Cu6—Cu6^i	5.5210 (4)
Cu1—Cu4	3.903 (4)	Cu6—Cu6^ii	4.3340 (4)
Cu1—Cu4^iii	3.903 (4)	Cu6—Cu6^iii	4.3340 (4)
Cu1—Cu4^vii	4.782 (3)	Cu6—Cu6^iv	5.5210 (4)
Cu1—Cu4^viii	4.782 (3)	Cu6—Cu7	3.939 (2)
Cu1—Cu4^xi	4.778 (3)	Cu6—Cu7^iii	3.939 (2)
Cu1—Cu4^x	4.778 (3)	Cu6—Cu7^iv	3.939 (2)
Cu1—Cu5	4.781 (4)	Cu6—Cu7^xiv	3.939 (2)
Cu1—Cu5^viii	5.512 (4)	Cu6—Cu7^xxviii	5.477 (4)
Cu1—Cu5^x	5.530 (4)	Cu6—Cu7^xxx	5.478 (4)
Cu1—Sn4	4.702 (3)	Cu6—Cu8^ii	4.598 (3)
Cu1—Sn4^iii	4.701 (3)	Cu6—Cu8	4.598 (3)
Cu1—Sn5	5.1184 (19)	Cu6—Cu8^xiii	4.598 (3)
Cu1—Sn5^iii	2.723 (3)	Cu6—Cu8^iv	4.598 (3)
Cu1—Sn5^xxvi	5.1183 (19)	Cu6—Cu10^xiii	4.830 (5)
Cu1—Sn5^xiv	4.773 (2)	Cu7—Cu7^i	5.5210 (4)
Cu1—Cu6^v	4.717 (3)	Cu7—Cu7^ii	4.3340 (4)
Cu1—Cu6	5.091 (2)	Cu7—Cu7^iii	4.3340 (4)
Cu1—Cu6^iii	2.671 (4)	Cu7—Cu7^iv	5.5210 (4)
Cu1—Cu6^xxvi	5.091 (2)	Cu7—Cu7^xxvii	3.655 (4)
Cu1—Cu7^iii	4.808 (4)	Cu7—Cu7^xxviii	3.654 (4)
Cu1—Cu7^xxvi	4.808 (4)	Cu7—Cu8^ii	4.759 (5)
Cu1—Cu8	2.6549 (15)	Cu8—Cu8^i	5.5210 (4)
Cu1—Cu8^iii	2.6550 (15)	Cu8—Cu8^ii	4.3340 (4)
Cu1—Cu8^iv	4.7341 (16)	Cu8—Cu8^iii	4.3340 (4)
Cu1—Cu8^xiv	4.7341 (16)	Cu8—Cu8^iv	5.5210 (4)
Cu1—Cu10	4.854 (3)	Cu8—Cu9	4.793 (5)
Cu1—Cu10^xiii	5.218 (2)	Cu8—Cu10^ii	3.972 (2)
Cu1—Cu10^iv	2.905 (4)	Cu8—Cu10	3.972 (2)
Cu1—Cu10^xiv	5.218 (2)	Cu8—Cu10^xiii	3.971 (2)
Cu2—Cu2^i	5.521 (2)	Cu8—Cu10^iv	3.971 (2)
Cu2—Cu2^ii	4.3340 (4)	Cu9—Cu9^i	5.5210 (4)
Cu2—Cu2^iii	4.3340 (4)	Cu9—Cu9^ii	4.3340 (4)
Cu2—Cu2^iv	5.521 (2)	Cu9—Cu9^iii	4.3340 (4)
Cu2—Cu2^xxvii	3.741 (3)	Cu9—Cu9^iv	5.5210 (4)
Cu2—Cu2^xxviii	3.740 (3)	Cu9—Cu9^xxiv	3.964 (2)
Cu2—Cu2^xxix	3.897 (3)	Cu9—Cu9^xii	3.964 (2)
Cu2—Cu2^xxx	3.897 (3)	Cu9—Cu9^xvi	3.964 (2)
Cu2—Cu2^xxxi	5.0813 (13)	Cu9—Cu9^vi	3.964 (2)
Cu2—Cu2^xxxii	2.653 (2)	Cu9—Cu10^ii	4.574 (3)
Cu2—Cu2^vii	5.0813 (13)	Cu9—Cu10	4.574 (3)
Cu2—Cu2^xxxiii	5.1972 (14)	Cu9—Cu10^xiii	4.575 (3)
Cu2—Cu2^xv	2.868 (2)	Cu9—Cu10^iv	4.575 (3)
Cu2—Cu2^xi	5.1972 (14)	Cu9—Cu10^xxiv	4.777 (5)
Cu2—Cu2^xxxiv	2.637 (3)	Cu10—Cu10^i	5.5210 (4)
Cu2—Cu2^xxxv	2.637 (3)	Cu10—Cu10^ii	4.3340 (4)
Cu2—Cu3^ii	3.924 (4)	Cu10—Cu10^iii	4.3340 (4)
Cu2—Cu3	3.924 (4)	Cu10—Cu10^iv	5.5210 (4)
Cu2—Cu3^xxvii	5.493 (4)

Symmetry codes: (i) x−1, y, z; (ii) x, y, z−1; (iii) x, y, z+1; (iv) x+1, y, z; (v) x−1, y, z+1; (vi) −x+1/2, −y+1/2, z+1/2; (vii) −x, y, −z−1/2; (viii) −x, y, −z+1/2; (ix) −x, y, −z+3/2; (x) −x+1, y, −z+1/2; (xi) −x+1, y, −z−1/2; (xii) −x−1/2, −y+1/2, z+1/2; (xiii) x+1, y, z−1; (xiv) x+1, y, z+1; (xv) −x+1, y, −z−3/2; (xvi) −x+1/2, −y+1/2, z−1/2; (xvii) −x+3/2, −y+1/2, z−1/2; (xviii) −x+3/2, −y+1/2, z+1/2; (xix) x+1/2, −y+1/2, −z−1; (xx) x+1/2, −y+1/2, −z; (xxi) −x+1/2, −y+1/2, z−3/2; (xxii) x−1/2, −y+1/2, −z; (xxiii) x+1/2, −y+1/2, −z+1; (xxiv) −x−1/2, −y+1/2, z−1/2; (xxv) −x+1, y, −z+3/2; (xxvi) x, y, z+2; (xxvii) −x, −y+1, z−1/2; (xxviii) −x, −y+1, z+1/2; (xxix) −x+1, −y+1, z−1/2; (xxx) −x+1, −y+1, z+1/2; (xxxi) −x, y, −z−5/2; (xxxii) −x, y, −z−3/2; (xxxiii) −x+1, y, −z−5/2; (xxxiv) x, −y+1, −z−2; (xxxv) x, −y+1, −z−1; (xxxvi) x−1, y, z−1; (xxxvii) −x+1, −y+1, z−3/2; (xxxviii) −x, −y+1, z+3/2; (xxxix) x−1/2, −y+1/2, −z+1; (xl) −x+1/2, −y+1/2, z+3/2; (xli) x+1, y, z+2; (xlii) −x+1, −y+1, z+3/2.

(573K-superstructure)

Crystal data

Cu3Sn	F(000) = 2740
Mr = 309.3	Dx = 8.994 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -C -2x;-2yc;-2zc	Cell parameters from 1456 reflections
a = 5.5185 (3) Å	θ = 3.4–28.1°
b = 47.768 (2) Å	µ = 37.92 mm^−1
c = 4.3320 (2) Å	T = 293 K
V = 1141.95 (9) Å^3	Trigonal prismatic, metallic dark grey
Z = 20	0.09 × 0.05 × 0.03 mm

Data collection

Xcalibur, Eos diffractometer	840 independent reflections
Radiation source: Enhance (Mo) X-ray Source	382 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.031
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.1°, θmin = 3.4°
ω scans	h = −6→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −62→62
Tmin = 0.227, Tmax = 0.551	l = −5→5
8193 measured reflections

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.029	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.107	(Δ/σ)max = 0.050
S = 1.62	Δρmax = 1.75 e Å^−3
840 reflections	Δρmin = −1.84 e Å^−3
72 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 194 (10)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0	0.33372 (3)	0.25	0.0076 (5)
Sn2	0.5	0.26613 (4)	0.75	0.0065 (5)
Sn3	0.5	0.36618 (4)	0.75	0.0062 (5)
Sn4	0.5	0.46628 (4)	0.75	0.0081 (5)
Cu1	0.5	0.43182 (7)	0.25	0.0073 (9)
Sn5	0	0.43330 (4)	0.25	0.0084 (5)
Cu2	0	0.46890 (7)	0.75	0.0062 (9)
Cu3	0	0.36954 (6)	0.75	0.0076 (9)
Cu4	0.2479 (2)	0.38404 (6)	0.25	0.0090 (9)
Cu5	0.2397 (3)	0.48422 (7)	0.25	0.0091 (8)
Cu6	0.2522 (2)	0.41579 (6)	0.75	0.0080 (9)
Cu7	0.2477 (2)	0.28404 (7)	0.25	0.0134 (10)
Cu8	0.2527 (2)	0.31579 (6)	0.75	0.0112 (10)
Cu9	0	0.26942 (7)	0.75	0.0125 (10)
Cu10	0.5	0.33085 (7)	0.25	0.0119 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0073 (9)	0.0073 (8)	0.0083 (11)	0	0	0
Sn2	0.0047 (8)	0.0070 (7)	0.0078 (9)	0	0	0
Sn3	0.0053 (9)	0.0054 (7)	0.0077 (10)	0	0	0
Sn4	0.0092 (9)	0.0065 (8)	0.0087 (10)	0	0	0
Cu1	0.0045 (16)	0.0138 (16)	0.0036 (17)	0	0	0
Sn5	0.0090 (10)	0.0083 (8)	0.0079 (10)	0	0	0
Cu2	0.0065 (16)	0.0075 (14)	0.0046 (16)	0	0	0
Cu3	0.0051 (16)	0.0077 (14)	0.0100 (17)	0	0	0
Cu4	0.0136 (18)	0.0071 (13)	0.0063 (17)	0.0005 (5)	0	0
Cu5	0.0106 (15)	0.0081 (12)	0.0088 (15)	−0.0006 (5)	0	0
Cu6	0.0092 (16)	0.0054 (14)	0.0092 (19)	0.0003 (5)	0	0
Cu7	0.0143 (17)	0.0147 (16)	0.0112 (18)	−0.0004 (5)	0	0
Cu8	0.0127 (17)	0.0122 (16)	0.0088 (18)	−0.0004 (5)	0	0
Cu9	0.0090 (16)	0.0161 (16)	0.0123 (17)	0	0	0
Cu10	0.0105 (18)	0.0154 (16)	0.0098 (19)	0	0	0

Bond lengths (Å)

Sn1—Cu3^i	2.760 (2)	Sn4—Cu6	2.773 (3)
Sn1—Cu3	2.760 (2)	Sn4—Cu6^viii	2.773 (3)
Sn1—Cu4	2.766 (3)	Cu1—Sn5	2.7602 (3)
Sn1—Cu4^ii	2.766 (3)	Cu1—Sn5^x	2.7602 (3)
Sn1—Cu7	2.739 (3)	Cu1—Cu4	2.673 (4)
Sn1—Cu7^ii	2.739 (3)	Cu1—Cu4^vii	2.673 (4)
Sn1—Cu8^i	2.7146 (12)	Cu1—Cu6^i	2.6736 (13)
Sn1—Cu8	2.7146 (12)	Cu1—Cu6	2.6736 (13)
Sn1—Cu8^ii	2.7146 (12)	Cu1—Cu6^vii	2.6736 (13)
Sn1—Cu8^iii	2.7146 (12)	Cu1—Cu6^viii	2.6736 (13)
Sn1—Cu10^iv	2.7626 (3)	Sn5—Cu2^i	2.754 (2)
Sn1—Cu10	2.7626 (3)	Sn5—Cu2	2.754 (2)
Sn2—Cu7	2.7131 (13)	Sn5—Cu4	2.722 (3)
Sn2—Cu7^v	2.7131 (13)	Sn5—Cu4^ii	2.722 (3)
Sn2—Cu7^vi	2.759 (3)	Sn5—Cu5	2.769 (3)
Sn2—Cu7^vii	2.7131 (13)	Sn5—Cu5^ii	2.769 (3)
Sn2—Cu7^viii	2.7131 (13)	Sn5—Cu6^i	2.7069 (12)
Sn2—Cu7^ix	2.759 (3)	Sn5—Cu6	2.7069 (12)
Sn2—Cu8	2.736 (3)	Sn5—Cu6^ii	2.7069 (12)
Sn2—Cu8^viii	2.736 (3)	Sn5—Cu6^iii	2.7069 (12)
Sn2—Cu9	2.7637 (4)	Cu2—Cu5	2.6415 (14)
Sn2—Cu9^x	2.7637 (4)	Cu2—Cu5^v	2.6415 (14)
Sn2—Cu9^xi	2.752 (2)	Cu2—Cu5^xiv	2.601 (4)
Sn2—Cu9^vi	2.752 (2)	Cu2—Cu5^ii	2.6415 (14)
Sn3—Cu3	2.7639 (4)	Cu2—Cu5^iii	2.6415 (14)
Sn3—Cu3^x	2.7639 (4)	Cu2—Cu5^xiii	2.601 (4)
Sn3—Cu4	2.7120 (13)	Cu3—Cu4	2.6538 (13)
Sn3—Cu4^v	2.7120 (13)	Cu3—Cu4^v	2.6538 (13)
Sn3—Cu4^vii	2.7120 (13)	Cu3—Cu4^ii	2.6538 (13)
Sn3—Cu4^viii	2.7120 (13)	Cu3—Cu4^iii	2.6538 (13)
Sn3—Cu6	2.736 (3)	Cu3—Cu6	2.611 (4)
Sn3—Cu6^viii	2.736 (3)	Cu3—Cu6^iii	2.611 (4)
Sn3—Cu8	2.767 (3)	Cu4—Cu6^i	2.644 (2)
Sn3—Cu8^viii	2.767 (3)	Cu4—Cu6	2.644 (2)
Sn3—Cu10	2.746 (2)	Cu5—Cu5^ii	2.646 (2)
Sn3—Cu10^v	2.746 (2)	Cu5—Cu5^xv	2.639 (3)
Sn4—Cu1	2.721 (2)	Cu5—Cu5^xiii	2.639 (3)
Sn4—Cu1^v	2.721 (2)	Cu7—Cu8^i	2.644 (2)
Sn4—Cu2	2.7621 (3)	Cu7—Cu8	2.644 (2)
Sn4—Cu2^x	2.7621 (3)	Cu7—Cu9^i	2.6549 (14)
Sn4—Cu5	2.7365 (14)	Cu7—Cu9	2.6549 (14)
Sn4—Cu5^v	2.7365 (14)	Cu7—Cu10	2.634 (4)
Sn4—Cu5^xii	2.767 (3)	Cu8—Cu9	2.617 (4)
Sn4—Cu5^vii	2.7365 (14)	Cu8—Cu10	2.6594 (13)
Sn4—Cu5^viii	2.7365 (14)	Cu8—Cu10^v	2.6594 (13)
Sn4—Cu5^xiii	2.767 (3)

Symmetry codes: (i) x, y, z−1; (ii) −x, y, −z+1/2; (iii) −x, y, −z+3/2; (iv) x−1, y, z; (v) x, y, z+1; (vi) −x+1/2, −y+1/2, z+1/2; (vii) −x+1, y, −z+1/2; (viii) −x+1, y, −z+3/2; (ix) x+1/2, −y+1/2, −z+1; (x) x+1, y, z; (xi) −x+1/2, −y+1/2, z−1/2; (xii) −x+1, −y+1, z+1/2; (xiii) x, −y+1, −z+1; (xiv) −x, −y+1, z+1/2; (xv) x, −y+1, −z.

(673K-superstructure)

Crystal data

Cu3Sn	F(000) = 2192
Mr = 309.3	Dx = 8.986 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -C -2x;-2yc;-2zc	Cell parameters from 2178 reflections
a = 5.5196 (1) Å	θ = 3.2–28.4°
b = 38.2386 (12) Å	µ = 37.89 mm^−1
c = 4.3321 (1) Å	T = 293 K
V = 914.34 (4) Å^3	Block, metallic intense silver
Z = 16	0.14 × 0.05 × 0.02 mm

Data collection

Xcalibur, Eos diffractometer	689 independent reflections
Radiation source: Enhance (Mo) X-ray Source	389 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.034
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.4°, θmin = 3.2°
ω and π scans	h = −7→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −49→50
Tmin = 0.095, Tmax = 0.529	l = −5→5
7324 measured reflections

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.026	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.097	(Δ/σ)max = 0.049
S = 1.96	Δρmax = 1.34 e Å^−3
689 reflections	Δρmin = −1.25 e Å^−3
58 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 225 (12)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0.5	0.29211 (2)	0.25	0.0068 (3)
Sn2	0	0.33254 (2)	0.75	0.0069 (3)
Sn3	0	0.45781 (3)	0.75	0.0087 (3)
Sn4	0.5	0.41656 (3)	0.25	0.0082 (3)
Cu1	0.5	0.46135 (5)	0.75	0.0083 (6)
Cu2	0	0.28811 (5)	0.25	0.0111 (6)
Cu3	0.26080 (17)	0.48005 (4)	0.25	0.0122 (5)
Cu4	0	0.41423 (5)	0.25	0.0081 (6)
Cu5	0.25216 (16)	0.23001 (4)	0.25	0.0112 (5)
Cu6	0.5	0.33687 (5)	0.75	0.0119 (6)
Cu7	0.25152 (15)	0.35505 (4)	0.25	0.0104 (5)
Cu8	0.24709 (15)	0.39472 (4)	0.75	0.0104 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0061 (5)	0.0075 (5)	0.0070 (6)	0	0	0
Sn2	0.0071 (6)	0.0062 (5)	0.0074 (6)	0	0	0
Sn3	0.0089 (6)	0.0083 (5)	0.0091 (7)	0	0	0
Sn4	0.0084 (6)	0.0082 (5)	0.0080 (6)	0	0	0
Cu1	0.0068 (9)	0.0108 (9)	0.0073 (11)	0	0	0
Cu2	0.0101 (10)	0.0127 (9)	0.0105 (12)	0	0	0
Cu3	0.0138 (9)	0.0123 (8)	0.0104 (9)	0.0014 (4)	0	0
Cu4	0.0065 (10)	0.0125 (9)	0.0052 (10)	0	0	0
Cu5	0.0132 (9)	0.0107 (8)	0.0097 (9)	0.0006 (3)	0	0
Cu6	0.0110 (11)	0.0135 (9)	0.0113 (11)	0	0	0
Cu7	0.0111 (10)	0.0111 (8)	0.0091 (11)	−0.0005 (3)	0	0
Cu8	0.0145 (10)	0.0093 (8)	0.0074 (10)	0.0003 (3)	0	0

Bond lengths (Å)

Sn1—Sn1^i	5.5196 (2)	Cu1—Cu3^iii	2.6355 (8)
Sn1—Sn1^ii	4.3321 (2)	Cu1—Cu3^iv	4.7785 (9)
Sn1—Sn1^iii	4.3321 (2)	Cu1—Cu3^x	4.7790 (9)
Sn1—Sn1^iv	5.5196 (2)	Cu1—Cu3^xxvii	4.7598 (14)
Sn1—Sn1^v	4.7623 (9)	Cu1—Cu3^xxix	5.0524 (11)
Sn1—Sn1^vi	4.7618 (9)	Cu1—Cu3^xxviii	2.601 (2)
Sn1—Sn1^vii	4.7624 (9)	Cu1—Cu3^xxxv	5.0530 (11)
Sn1—Sn1^viii	4.7625 (9)	Cu1—Cu3^xi	4.7791 (9)
Sn1—Sn2^ii	3.8341 (5)	Cu1—Cu3^xxii	4.7787 (9)
Sn1—Sn2	3.8339 (5)	Cu1—Cu3^xiii	2.6354 (8)
Sn1—Sn2^ix	3.8335 (5)	Cu1—Cu3^xiv	2.6357 (8)
Sn1—Sn2^iv	3.8340 (5)	Cu1—Cu3^xxxii	5.0528 (11)
Sn1—Sn2^v	4.7664 (13)	Cu1—Cu3^xxxiii	2.601 (2)
Sn1—Sn4	4.7587 (14)	Cu1—Cu3^xxxiv	5.0528 (11)
Sn1—Cu2^ii	5.1391 (2)	Cu1—Cu3^xxxvi	4.7594 (14)
Sn1—Cu2	2.7640 (1)	Cu1—Cu4	3.9440 (12)
Sn1—Cu2^iii	5.1385 (2)	Cu1—Cu4^iii	3.9435 (12)
Sn1—Cu2^ix	5.1385 (2)	Cu1—Cu4^iv	3.9439 (12)
Sn1—Cu2^iv	2.7641 (1)	Cu1—Cu4^x	3.9442 (12)
Sn1—Cu2^x	5.1391 (2)	Cu1—Cu4^xxvii	5.500 (2)
Sn1—Cu2^v	3.7552 (17)	Cu1—Cu4^xxviii	5.500 (2)
Sn1—Cu2^vi	3.7549 (17)	Cu1—Cu6	4.760 (3)
Sn1—Cu4	5.4247 (18)	Cu1—Cu7	4.806 (2)
Sn1—Cu4^iv	5.4242 (18)	Cu1—Cu7^iii	4.806 (2)
Sn1—Cu5^ii	5.1264 (9)	Cu1—Cu7^xiii	4.806 (2)
Sn1—Cu5	2.7404 (16)	Cu1—Cu7^xiv	4.806 (2)
Sn1—Cu5^iii	5.1258 (9)	Cu1—Cu8^ii	5.2164 (12)
Sn1—Cu5^iv	4.7830 (12)	Cu1—Cu8	2.905 (2)
Sn1—Cu5^v	2.7101 (7)	Cu1—Cu8^iii	5.2158 (12)
Sn1—Cu5^vi	2.7098 (7)	Cu1—Cu8^iv	4.8476 (14)
Sn1—Cu5^vii	4.7375 (8)	Cu1—Cu8^xxii	4.8471 (14)
Sn1—Cu5^viii	4.7379 (8)	Cu1—Cu8^xiii	5.2162 (12)
Sn1—Cu5^xi	4.7826 (12)	Cu1—Cu8^xiv	2.905 (2)
Sn1—Cu5^xii	5.1262 (9)	Cu1—Cu8^xxxvii	5.2162 (12)
Sn1—Cu5^xiii	2.7406 (16)	Cu2—Cu2^i	5.5196 (2)
Sn1—Cu5^xiv	5.1262 (9)	Cu2—Cu2^ii	4.3321 (2)
Sn1—Cu5^xv	4.7378 (8)	Cu2—Cu2^iii	4.3321 (2)
Sn1—Cu5^xvi	4.7373 (8)	Cu2—Cu2^iv	5.5196 (2)
Sn1—Cu5^xvii	2.7099 (7)	Cu2—Cu2^xxxviii	4.5610 (16)
Sn1—Cu5^xviii	2.7101 (7)	Cu2—Cu2^xx	4.5605 (16)
Sn1—Cu6^ii	2.7607 (13)	Cu2—Cu2^v	4.5610 (16)
Sn1—Cu6	2.7609 (13)	Cu2—Cu2^vi	4.5612 (16)
Sn1—Cu6^v	5.6514 (19)	Cu2—Cu4	4.823 (3)
Sn1—Cu6^vii	5.6519 (19)	Cu2—Cu5^i	4.6875 (14)
Sn1—Cu7^ii	5.1421 (9)	Cu2—Cu5^ii	5.0637 (11)
Sn1—Cu7	2.7703 (16)	Cu2—Cu5	2.622 (2)
Sn1—Cu7^iii	5.1421 (9)	Cu2—Cu5^iii	5.0637 (11)
Sn1—Cu7^iv	4.7955 (12)	Cu2—Cu5^xxxviii	4.7338 (9)
Sn1—Cu7^xi	4.7960 (12)	Cu2—Cu5^xx	4.7333 (9)
Sn1—Cu7^xii	5.1417 (9)	Cu2—Cu5^v	2.6538 (8)
Sn1—Cu7^xiii	2.7700 (16)	Cu2—Cu5^vi	2.6540 (8)
Sn1—Cu7^xiv	5.1423 (9)	Cu2—Cu5^xxxix	5.0638 (11)
Sn1—Cu8^ii	4.6942 (15)	Cu2—Cu5^xi	2.622 (2)
Sn1—Cu8	4.6943 (15)	Cu2—Cu5^xxii	5.0633 (11)
Sn1—Cu8^xiii	4.6938 (15)	Cu2—Cu5^xiii	4.6879 (14)
Sn1—Cu8^xiv	4.6943 (15)	Cu2—Cu5^xv	2.6540 (8)
Sn2—Sn2^i	5.5196 (2)	Cu2—Cu5^xvi	2.6536 (8)
Sn2—Sn2^ii	4.3321 (2)	Cu2—Cu5^xvii	4.7335 (9)
Sn2—Sn2^iii	4.3321 (2)	Cu2—Cu5^xviii	4.7339 (9)
Sn2—Sn2^iv	5.5196 (2)	Cu2—Cu6^xxiv	3.9733 (12)
Sn2—Sn3	4.7902 (14)	Cu2—Cu6^i	3.9731 (12)
Sn2—Sn4^i	4.7573 (9)	Cu2—Cu6^ii	3.9727 (12)
Sn2—Sn4^xix	4.7572 (9)	Cu2—Cu6	3.9732 (12)
Sn2—Sn4	4.7566 (9)	Cu2—Cu6^v	4.779 (3)
Sn2—Sn4^iii	4.7571 (9)	Cu2—Cu7^i	4.8603 (14)
Sn2—Cu1^i	5.6463 (18)	Cu2—Cu7^ii	5.2195 (12)
Sn2—Cu1	5.6458 (18)	Cu2—Cu7	2.912 (2)
Sn2—Cu2	2.7530 (13)	Cu2—Cu7^iii	5.2200 (12)
Sn2—Cu2^iii	2.7528 (13)	Cu2—Cu7^xxxix	5.2199 (12)
Sn2—Cu2^xx	5.3757 (18)	Cu2—Cu7^xi	2.912 (2)
Sn2—Cu2^vi	5.3762 (18)	Cu2—Cu7^xxii	5.2199 (12)
Sn2—Cu4	3.8012 (17)	Cu2—Cu7^xiii	4.8598 (14)
Sn2—Cu4^iii	3.8014 (17)	Cu2—Cu8^ii	4.813 (2)
Sn2—Cu5	4.6907 (16)	Cu2—Cu8	4.814 (2)
Sn2—Cu5^iii	4.6906 (16)	Cu2—Cu8^xi	4.814 (2)
Sn2—Cu5^xx	4.7911 (12)	Cu2—Cu8^xxii	4.814 (2)
Sn2—Cu5^v	5.1342 (9)	Cu3—Cu3^i	5.5196 (13)
Sn2—Cu5^vi	2.7555 (16)	Cu3—Cu3^ii	4.3321 (2)
Sn2—Cu5^xxi	5.1342 (9)	Cu3—Cu3^iii	4.3321 (2)
Sn2—Cu5^xi	4.6906 (16)	Cu3—Cu3^iv	5.5196 (13)
Sn2—Cu5^xxii	4.6902 (16)	Cu3—Cu3^xxvi	3.9127 (13)
Sn2—Cu5^xv	5.1343 (9)	Cu3—Cu3^xxvii	3.9124 (13)
Sn2—Cu5^xvi	2.7552 (16)	Cu3—Cu3^xxix	3.7401 (13)
Sn2—Cu5^xxiii	5.1337 (9)	Cu3—Cu3^xxviii	3.7406 (13)
Sn2—Cu5^xviii	4.7915 (12)	Cu3—Cu3^xxxix	5.2018 (8)
Sn2—Cu6^xxiv	5.1394 (2)	Cu3—Cu3^xi	2.8790 (13)
Sn2—Cu6^i	2.7648 (2)	Cu3—Cu3^xxii	5.2012 (8)
Sn2—Cu6^xix	5.1389 (2)	Cu3—Cu3^xii	5.0732 (7)
Sn2—Cu6^ii	5.1389 (2)	Cu3—Cu3^xiii	2.6406 (13)
Sn2—Cu6	2.7648 (2)	Cu3—Cu3^xiv	5.0737 (7)
Sn2—Cu6^iii	5.1395 (2)	Cu3—Cu3^xxxii	2.6492 (13)
Sn2—Cu7^i	4.7437 (8)	Cu3—Cu3^xxxiii	2.6494 (13)
Sn2—Cu7^xix	4.7433 (8)	Cu3—Cu4^ii	5.2131 (12)
Sn2—Cu7	2.7127 (7)	Cu3—Cu4	2.899 (2)
Sn2—Cu7^iii	2.7130 (7)	Cu3—Cu4^iii	5.2125 (12)
Sn2—Cu7^xi	2.7130 (7)	Cu3—Cu4^iv	4.7942 (15)
Sn2—Cu7^xxii	2.7129 (7)	Cu3—Cu4^xxvi	4.807 (2)
Sn2—Cu7^xiii	4.7431 (8)	Cu3—Cu4^xxvii	4.807 (2)
Sn2—Cu7^xiv	4.7436 (8)	Cu3—Cu7	4.780 (2)
Sn2—Cu8^i	4.7880 (12)	Cu3—Cu7^xi	5.554 (2)
Sn2—Cu8^ii	5.1260 (9)	Cu3—Cu7^xiii	5.486 (2)
Sn2—Cu8	2.7408 (16)	Cu3—Cu8^ii	3.9175 (18)
Sn2—Cu8^iii	5.1266 (9)	Cu3—Cu8	3.9172 (18)
Sn2—Cu8^xi	5.1265 (9)	Cu3—Cu8^xxvi	5.549 (2)
Sn2—Cu8^xxii	2.7411 (16)	Cu3—Cu8^xxix	5.505 (2)
Sn2—Cu8^xxv	5.1265 (9)	Cu3—Cu8^xi	4.8166 (17)
Sn2—Cu8^xiv	4.7876 (12)	Cu3—Cu8^xxii	4.8161 (17)
Sn3—Sn3^i	5.5196 (2)	Cu3—Cu8^xiii	4.7665 (17)
Sn3—Sn3^ii	4.3321 (2)	Cu3—Cu8^xiv	4.7666 (17)
Sn3—Sn3^iii	4.3321 (2)	Cu3—Cu8^xxxiii	4.789 (2)
Sn3—Sn3^iv	5.5196 (2)	Cu4—Cu4^i	5.5196 (2)
Sn3—Sn3^xxvi	3.8859 (11)	Cu4—Cu4^ii	4.3321 (2)
Sn3—Sn3^xxvii	3.8862 (11)	Cu4—Cu4^iii	4.3321 (2)
Sn3—Sn4^i	3.8468 (6)	Cu4—Cu4^iv	5.5196 (2)
Sn3—Sn4^xix	3.8463 (6)	Cu4—Cu6^xxiv	4.5891 (17)
Sn3—Sn4	3.8467 (6)	Cu4—Cu6^i	4.5886 (17)
Sn3—Sn4^iii	3.8469 (6)	Cu4—Cu6^ii	4.5891 (17)
Sn3—Sn4^xxvii	5.5405 (12)	Cu4—Cu6	4.5893 (17)
Sn3—Sn4^xxviii	5.5400 (12)	Cu4—Cu7^i	4.7104 (14)
Sn3—Cu1^xxiv	5.1386 (2)	Cu4—Cu7^ii	5.0810 (11)
Sn3—Cu1^i	2.7631 (1)	Cu4—Cu7	2.655 (2)
Sn3—Cu1^xix	5.1380 (2)	Cu4—Cu7^iii	5.0810 (11)
Sn3—Cu1^ii	5.1380 (2)	Cu4—Cu7^xxxix	5.0812 (11)
Sn3—Cu1	2.7631 (1)	Cu4—Cu7^xi	2.655 (2)
Sn3—Cu1^iii	5.1386 (2)	Cu4—Cu7^xxii	5.0806 (11)
Sn3—Cu1^xxvi	4.6760 (13)	Cu4—Cu7^xiii	4.7108 (14)
Sn3—Cu1^xxvii	4.6759 (13)	Cu4—Cu8^xxiv	4.7456 (8)
Sn3—Cu1^xxix	4.6753 (13)	Cu4—Cu8^i	4.7451 (8)
Sn3—Cu1^xxviii	4.6758 (13)	Cu4—Cu8^ii	2.6662 (8)
Sn3—Cu3^i	4.6973 (9)	Cu4—Cu8	2.6664 (8)
Sn3—Cu3^xix	4.6969 (9)	Cu4—Cu8^xi	2.6664 (8)
Sn3—Cu3	2.7361 (8)	Cu4—Cu8^xxii	2.6660 (8)
Sn3—Cu3^iii	2.7364 (8)	Cu4—Cu8^xiii	4.7453 (8)
Sn3—Cu3^xxvi	5.1464 (9)	Cu4—Cu8^xiv	4.7457 (8)
Sn3—Cu3^xxvii	2.7781 (17)	Cu5—Cu5^i	5.5196 (12)
Sn3—Cu3^xxx	5.1463 (9)	Cu5—Cu5^ii	4.3321 (2)
Sn3—Cu3^xxviii	4.7212 (12)	Cu5—Cu5^iii	4.3321 (2)
Sn3—Cu3^xi	2.7364 (8)	Cu5—Cu5^iv	5.5196 (12)
Sn3—Cu3^xxii	2.7362 (8)	Cu5—Cu5^v	2.6514 (13)
Sn3—Cu3^xiii	4.6967 (9)	Cu5—Cu5^vi	2.6515 (13)
Sn3—Cu3^xiv	4.6972 (9)	Cu5—Cu5^xxxix	5.1496 (7)
Sn3—Cu3^xxxi	4.7217 (12)	Cu5—Cu5^xi	2.7836 (12)
Sn3—Cu3^xxxii	5.1459 (9)	Cu5—Cu5^xxii	5.1491 (7)
Sn3—Cu3^xxxiii	2.7778 (17)	Cu5—Cu5^xii	5.1234 (7)
Sn3—Cu3^xxxiv	5.1465 (9)	Cu5—Cu5^xiii	2.7360 (12)
Sn3—Cu4	2.7330 (13)	Cu5—Cu5^xiv	5.1240 (7)
Sn3—Cu4^iii	2.7328 (13)	Cu5—Cu5^xv	3.8273 (13)
Sn3—Cu4^xxvii	4.893 (2)	Cu5—Cu5^xvi	3.8270 (13)
Sn3—Cu6^i	5.3852 (19)	Cu5—Cu5^xvii	3.8267 (13)
Sn3—Cu6	5.3857 (19)	Cu5—Cu5^xviii	3.8272 (13)
Sn3—Cu7	4.6970 (15)	Cu5—Cu6^ii	4.823 (2)
Sn3—Cu7^iii	4.6969 (15)	Cu5—Cu6	4.823 (2)
Sn3—Cu7^xi	4.6969 (15)	Cu5—Cu6^xl	5.2198 (13)
Sn3—Cu7^xxii	4.6965 (15)	Cu5—Cu6^v	2.911 (2)
Sn3—Cu8^i	4.8051 (12)	Cu5—Cu6^vi	5.2193 (13)
Sn3—Cu8^ii	5.1428 (9)	Cu5—Cu6^vii	4.8560 (15)
Sn3—Cu8	2.7716 (16)	Cu5—Cu7	4.781 (2)
Sn3—Cu8^iii	5.1428 (9)	Cu5—Cu7^v	3.9079 (18)
Sn3—Cu8^xi	5.1430 (9)	Cu5—Cu7^vi	3.9076 (18)
Sn3—Cu8^xxii	2.7713 (16)	Cu5—Cu7^xi	5.531 (2)
Sn3—Cu8^xxv	5.1424 (9)	Cu5—Cu7^xiii	5.510 (2)
Sn3—Cu8^xiv	4.8055 (12)	Cu5—Cu7^xv	4.7861 (16)
Sn4—Sn4^i	5.5196 (2)	Cu5—Cu7^xvi	4.7856 (16)
Sn4—Sn4^ii	4.3321 (2)	Cu5—Cu7^xvii	4.7821 (16)
Sn4—Sn4^iii	4.3321 (2)	Cu5—Cu7^xviii	4.7822 (16)
Sn4—Sn4^iv	5.5196 (2)	Cu5—Cu8^v	4.769 (2)
Sn4—Cu1^ii	2.7614 (12)	Cu5—Cu8^xvi	5.524 (2)
Sn4—Cu1	2.7616 (12)	Cu5—Cu8^xviii	5.497 (2)
Sn4—Cu1^xxix	4.669 (2)	Cu6—Cu6^i	5.5196 (2)
Sn4—Cu2	5.6337 (18)	Cu6—Cu6^ii	4.3321 (2)
Sn4—Cu2^iv	5.6342 (18)	Cu6—Cu6^iii	4.3321 (2)
Sn4—Cu3^ii	5.1387 (9)	Cu6—Cu6^iv	5.5196 (2)
Sn4—Cu3	2.7639 (17)	Cu6—Cu7	2.6564 (8)
Sn4—Cu3^iii	5.1387 (9)	Cu6—Cu7^iii	2.6562 (8)
Sn4—Cu3^iv	4.8505 (12)	Cu6—Cu7^iv	4.7306 (8)
Sn4—Cu3^xxix	4.6970 (16)	Cu6—Cu7^x	4.7311 (8)
Sn4—Cu3^xxviii	4.6974 (16)	Cu6—Cu7^xi	4.7312 (8)
Sn4—Cu3^xi	4.8510 (12)	Cu6—Cu7^xxii	4.7307 (8)
Sn4—Cu3^xii	5.1383 (9)	Cu6—Cu7^xiii	2.6561 (8)
Sn4—Cu3^xiii	2.7637 (17)	Cu6—Cu7^xiv	2.6564 (8)
Sn4—Cu3^xiv	5.1389 (9)	Cu6—Cu8^ii	5.0605 (11)
Sn4—Cu3^xxxii	4.6974 (16)	Cu6—Cu8	2.616 (2)
Sn4—Cu3^xxxiii	4.6975 (16)	Cu6—Cu8^iii	5.0605 (11)
Sn4—Cu4^ii	5.1375 (2)	Cu6—Cu8^iv	4.6792 (14)
Sn4—Cu4	2.7612 (1)	Cu6—Cu8^xxii	4.6796 (14)
Sn4—Cu4^iii	5.1370 (2)	Cu6—Cu8^xiii	5.0601 (11)
Sn4—Cu4^ix	5.1370 (2)	Cu6—Cu8^xiv	2.615 (2)
Sn4—Cu4^iv	2.7612 (1)	Cu6—Cu8^xxxvii	5.0607 (11)
Sn4—Cu4^x	5.1375 (2)	Cu7—Cu7^i	5.5196 (12)
Sn4—Cu6^ii	3.7385 (18)	Cu7—Cu7^ii	4.3321 (2)
Sn4—Cu6	3.7383 (18)	Cu7—Cu7^iii	4.3321 (2)
Sn4—Cu7^ii	5.1168 (9)	Cu7—Cu7^iv	5.5196 (12)
Sn4—Cu7	2.7225 (16)	Cu7—Cu7^xxxix	5.1458 (7)
Sn4—Cu7^iii	5.1163 (9)	Cu7—Cu7^xi	2.7765 (12)
Sn4—Cu7^iv	4.7687 (12)	Cu7—Cu7^xxii	5.1452 (7)
Sn4—Cu7^xi	4.7682 (12)	Cu7—Cu7^xii	5.1272 (7)
Sn4—Cu7^xii	5.1167 (9)	Cu7—Cu7^xiii	2.7431 (12)
Sn4—Cu7^xiii	2.7228 (16)	Cu7—Cu7^xiv	5.1278 (7)
Sn4—Cu7^xiv	5.1167 (9)	Cu7—Cu8^ii	2.6444 (12)
Sn4—Cu8^ii	2.7090 (7)	Cu7—Cu8	2.6446 (12)
Sn4—Cu8	2.7086 (7)	Cu7—Cu8^xi	3.8169 (12)
Sn4—Cu8^ix	4.7321 (8)	Cu7—Cu8^xxii	3.8166 (12)
Sn4—Cu8^iv	4.7325 (8)	Cu7—Cu8^xiii	3.8274 (12)
Sn4—Cu8^xi	4.7324 (8)	Cu7—Cu8^xiv	3.8279 (12)
Sn4—Cu8^xxii	4.7319 (8)	Cu8—Cu8^i	5.5196 (12)
Sn4—Cu8^xiii	2.7088 (7)	Cu8—Cu8^ii	4.3321 (2)
Sn4—Cu8^xiv	2.7090 (7)	Cu8—Cu8^iii	4.3321 (2)
Cu1—Cu1^i	5.5196 (2)	Cu8—Cu8^iv	5.5196 (12)
Cu1—Cu1^ii	4.3321 (2)	Cu8—Cu8^xi	5.1196 (7)
Cu1—Cu1^iii	4.3321 (2)	Cu8—Cu8^xxii	2.7277 (12)
Cu1—Cu1^iv	5.5196 (2)	Cu8—Cu8^xxv	5.1190 (7)
Cu1—Cu1^xxix	3.664 (2)	Cu8—Cu8^xiii	5.1535 (7)
Cu1—Cu1^xxviii	3.665 (2)	Cu8—Cu8^xiv	2.7919 (12)
Cu1—Cu3	2.6357 (8)	Cu8—Cu8^xxxvii	5.1541 (7)

Symmetry codes: (i) x−1, y, z; (ii) x, y, z−1; (iii) x, y, z+1; (iv) x+1, y, z; (v) −x+1/2, −y+1/2, z−1/2; (vi) −x+1/2, −y+1/2, z+1/2; (vii) −x+3/2, −y+1/2, z−1/2; (viii) −x+3/2, −y+1/2, z+1/2; (ix) x+1, y, z−1; (x) x+1, y, z+1; (xi) −x, y, −z+1/2; (xii) −x+1, y, −z−1/2; (xiii) −x+1, y, −z+1/2; (xiv) −x+1, y, −z+3/2; (xv) x−1/2, −y+1/2, −z; (xvi) x−1/2, −y+1/2, −z+1; (xvii) x+1/2, −y+1/2, −z; (xviii) x+1/2, −y+1/2, −z+1; (xix) x−1, y, z+1; (xx) −x−1/2, −y+1/2, z+1/2; (xxi) −x+1/2, −y+1/2, z+3/2; (xxii) −x, y, −z+3/2; (xxiii) x−1/2, −y+1/2, −z+2; (xxiv) x−1, y, z−1; (xxv) −x, y, −z+5/2; (xxvi) −x, −y+1, z−1/2; (xxvii) −x, −y+1, z+1/2; (xxviii) −x+1, −y+1, z+1/2; (xxix) −x+1, −y+1, z−1/2; (xxx) −x, −y+1, z+3/2; (xxxi) x−1, −y+1, −z+1; (xxxii) x, −y+1, −z; (xxxiii) x, −y+1, −z+1; (xxxiv) x, −y+1, −z+2; (xxxv) −x+1, −y+1, z+3/2; (xxxvi) x+1, −y+1, −z+1; (xxxvii) −x+1, y, −z+5/2; (xxxviii) −x−1/2, −y+1/2, z−1/2; (xxxix) −x, y, −z−1/2; (xl) −x+1/2, −y+1/2, z−3/2.

(723K-superstructure)

Crystal data

Cu3Sn	F(000) = 2192
Mr = 309.3	Dx = 8.988 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -C -2x;-2yc;-2zc	Cell parameters from 1730 reflections
a = 5.5184 (2) Å	θ = 3.7–28.3°
b = 38.2337 (15) Å	µ = 37.89 mm^−1
c = 4.3326 (2) Å	T = 293 K
V = 914.13 (6) Å^3	Trigonal primatic, metallic grey
Z = 16	0.10 × 0.07 × 0.04 mm

Data collection

Xcalibur, Eos diffractometer	673 independent reflections
Radiation source: Enhance (Mo) X-ray Source	384 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.3°, θmin = 3.7°
ω and π scans	h = −7→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −48→49
Tmin = 0.199, Tmax = 0.434	l = −5→5
5405 measured reflections

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.022	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.063	(Δ/σ)max = 0.033
S = 1.26	Δρmax = 1.55 e Å^−3
673 reflections	Δρmin = −1.60 e Å^−3
58 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 570 (12)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0.5	0.292227 (17)	0.25	0.0095 (2)
Sn2	0	0.332569 (16)	0.75	0.0089 (2)
Sn3	0	0.457737 (17)	0.75	0.0095 (2)
Sn4	0.5	0.416506 (17)	0.25	0.0093 (2)
Cu1	0.5	0.46133 (3)	0.75	0.0125 (4)
Cu2	0	0.28840 (3)	0.25	0.0134 (4)
Cu3	0.26168 (12)	0.48009 (3)	0.25	0.0132 (3)
Cu4	0	0.41409 (3)	0.25	0.0114 (4)
Cu5	0.25213 (11)	0.23017 (3)	0.25	0.0116 (3)
Cu6	0.5	0.33679 (4)	0.75	0.0124 (4)
Cu7	0.25115 (10)	0.35503 (3)	0.25	0.0132 (4)
Cu8	0.24682 (10)	0.39476 (3)	0.75	0.0124 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0082 (4)	0.0093 (4)	0.0109 (4)	0	0	0
Sn2	0.0076 (4)	0.0096 (4)	0.0095 (4)	0	0	0
Sn3	0.0081 (4)	0.0092 (4)	0.0113 (4)	0	0	0
Sn4	0.0084 (4)	0.0088 (4)	0.0106 (4)	0	0	0
Cu1	0.0096 (7)	0.0154 (7)	0.0124 (7)	0	0	0
Cu2	0.0117 (7)	0.0152 (7)	0.0132 (7)	0	0	0
Cu3	0.0137 (6)	0.0123 (5)	0.0137 (6)	0.0012 (3)	0	0
Cu4	0.0097 (7)	0.0137 (6)	0.0106 (7)	0	0	0
Cu5	0.0121 (6)	0.0126 (5)	0.0102 (6)	0.0005 (2)	0	0
Cu6	0.0096 (7)	0.0158 (6)	0.0119 (7)	0	0	0
Cu7	0.0138 (8)	0.0132 (6)	0.0124 (7)	−0.0002 (2)	0	0
Cu8	0.0140 (7)	0.0123 (6)	0.0109 (7)	0.0004 (2)	0	0

Bond lengths (Å)

Sn1—Sn1^i	5.5184 (4)	Cu1—Cu3^iii	2.6338 (6)
Sn1—Sn1^ii	4.3326 (4)	Cu1—Cu3^iv	4.7828 (7)
Sn1—Sn1^iii	4.3326 (4)	Cu1—Cu3^x	4.7828 (7)
Sn1—Sn1^iv	5.5184 (4)	Cu1—Cu3^xxvii	4.7626 (10)
Sn1—Sn1^v	4.7679 (7)	Cu1—Cu3^xxix	5.0514 (9)
Sn1—Sn1^vi	4.7679 (7)	Cu1—Cu3^xxviii	2.5971 (15)
Sn1—Sn1^vii	4.7679 (7)	Cu1—Cu3^xxxv	5.0514 (9)
Sn1—Sn1^viii	4.7679 (7)	Cu1—Cu3^xi	4.7828 (7)
Sn1—Sn2^ii	3.8321 (4)	Cu1—Cu3^xxii	4.7828 (7)
Sn1—Sn2	3.8321 (4)	Cu1—Cu3^xiii	2.6338 (6)
Sn1—Sn2^ix	3.8321 (4)	Cu1—Cu3^xiv	2.6338 (6)
Sn1—Sn2^iv	3.8321 (4)	Cu1—Cu3^xxxii	5.0514 (9)
Sn1—Sn2^v	4.7714 (10)	Cu1—Cu3^xxxiii	2.5971 (15)
Sn1—Sn4	4.7516 (10)	Cu1—Cu3^xxxiv	5.0514 (9)
Sn1—Cu2^ii	5.1387 (4)	Cu1—Cu3^xxxvi	4.7626 (10)
Sn1—Cu2	2.7631 (2)	Cu1—Cu4	3.9457 (8)
Sn1—Cu2^iii	5.1387 (4)	Cu1—Cu4^iii	3.9457 (8)
Sn1—Cu2^ix	5.1387 (4)	Cu1—Cu4^iv	3.9457 (8)
Sn1—Cu2^iv	2.7631 (2)	Cu1—Cu4^x	3.9457 (8)
Sn1—Cu2^x	5.1387 (4)	Cu1—Cu4^xxvii	5.5045 (16)
Sn1—Cu2^v	3.7677 (12)	Cu1—Cu4^xxviii	5.5045 (16)
Sn1—Cu2^vi	3.7677 (12)	Cu1—Cu6	4.7616 (19)
Sn1—Cu4	5.4150 (13)	Cu1—Cu7	4.8060 (15)
Sn1—Cu4^iv	5.4150 (13)	Cu1—Cu7^iii	4.8060 (15)
Sn1—Cu5^ii	5.1257 (7)	Cu1—Cu7^xiii	4.8060 (15)
Sn1—Cu5	2.7389 (12)	Cu1—Cu7^xiv	4.8060 (15)
Sn1—Cu5^iii	5.1257 (7)	Cu1—Cu8^ii	5.2155 (9)
Sn1—Cu5^iv	4.7809 (9)	Cu1—Cu8	2.9035 (15)
Sn1—Cu5^v	2.7133 (5)	Cu1—Cu8^iii	5.2155 (9)
Sn1—Cu5^vi	2.7133 (5)	Cu1—Cu8^iv	4.8439 (10)
Sn1—Cu5^vii	4.7390 (6)	Cu1—Cu8^xxii	4.8439 (10)
Sn1—Cu5^viii	4.7390 (6)	Cu1—Cu8^xiii	5.2155 (9)
Sn1—Cu5^xi	4.7809 (9)	Cu1—Cu8^xiv	2.9035 (15)
Sn1—Cu5^xii	5.1257 (7)	Cu1—Cu8^xxxvii	5.2155 (9)
Sn1—Cu5^xiii	2.7389 (12)	Cu2—Cu2^i	5.5184 (4)
Sn1—Cu5^xiv	5.1257 (7)	Cu2—Cu2^ii	4.3326 (4)
Sn1—Cu5^xv	4.7390 (6)	Cu2—Cu2^iii	4.3326 (4)
Sn1—Cu5^xvi	4.7390 (6)	Cu2—Cu2^iv	5.5184 (4)
Sn1—Cu5^xvii	2.7133 (5)	Cu2—Cu2^xxxviii	4.5746 (11)
Sn1—Cu5^xviii	2.7133 (5)	Cu2—Cu2^xx	4.5746 (11)
Sn1—Cu6^ii	2.7561 (9)	Cu2—Cu2^v	4.5746 (11)
Sn1—Cu6	2.7561 (9)	Cu2—Cu2^vi	4.5746 (11)
Sn1—Cu6^v	5.6521 (13)	Cu2—Cu4	4.8057 (18)
Sn1—Cu6^vii	5.6521 (13)	Cu2—Cu5^i	4.6893 (10)
Sn1—Cu7^ii	5.1403 (7)	Cu2—Cu5^ii	5.0660 (8)
Sn1—Cu7	2.7662 (12)	Cu2—Cu5	2.6254 (15)
Sn1—Cu7^iii	5.1403 (7)	Cu2—Cu5^iii	5.0660 (8)
Sn1—Cu7^iv	4.7904 (9)	Cu2—Cu5^xxxviii	4.7354 (6)
Sn1—Cu7^xi	4.7904 (9)	Cu2—Cu5^xx	4.7354 (6)
Sn1—Cu7^xii	5.1403 (7)	Cu2—Cu5^v	2.6585 (6)
Sn1—Cu7^xiii	2.7662 (12)	Cu2—Cu5^vi	2.6585 (6)
Sn1—Cu7^xiv	5.1403 (7)	Cu2—Cu5^xxxix	5.0660 (8)
Sn1—Cu8^ii	4.6918 (11)	Cu2—Cu5^xi	2.6254 (15)
Sn1—Cu8	4.6918 (11)	Cu2—Cu5^xxii	5.0660 (8)
Sn1—Cu8^xiii	4.6918 (11)	Cu2—Cu5^xiii	4.6893 (10)
Sn1—Cu8^xiv	4.6918 (11)	Cu2—Cu5^xv	2.6585 (6)
Sn2—Sn2^i	5.5184 (4)	Cu2—Cu5^xvi	2.6585 (6)
Sn2—Sn2^ii	4.3326 (4)	Cu2—Cu5^xvii	4.7354 (6)
Sn2—Sn2^iii	4.3326 (4)	Cu2—Cu5^xviii	4.7354 (6)
Sn2—Sn2^iv	5.5184 (4)	Cu2—Cu6^xxiv	3.9661 (9)
Sn2—Sn3	4.7856 (10)	Cu2—Cu6^i	3.9661 (9)
Sn2—Sn4^i	4.7545 (6)	Cu2—Cu6^ii	3.9661 (9)
Sn2—Sn4^xix	4.7545 (6)	Cu2—Cu6	3.9661 (9)
Sn2—Sn4	4.7545 (6)	Cu2—Cu6^v	4.7865 (19)
Sn2—Sn4^iii	4.7545 (6)	Cu2—Cu7^i	4.8546 (10)
Sn2—Cu1^i	5.6436 (13)	Cu2—Cu7^ii	5.2137 (9)
Sn2—Cu1	5.6436 (13)	Cu2—Cu7	2.9002 (15)
Sn2—Cu2	2.7468 (9)	Cu2—Cu7^iii	5.2137 (9)
Sn2—Cu2^iii	2.7468 (9)	Cu2—Cu7^xxxix	5.2137 (9)
Sn2—Cu2^xx	5.3855 (12)	Cu2—Cu7^xi	2.9002 (15)
Sn2—Cu2^vi	5.3855 (12)	Cu2—Cu7^xxii	5.2137 (9)
Sn2—Cu4	3.7958 (12)	Cu2—Cu7^xiii	4.8546 (10)
Sn2—Cu4^iii	3.7958 (12)	Cu2—Cu8^ii	4.8047 (14)
Sn2—Cu5	4.6859 (12)	Cu2—Cu8	4.8047 (14)
Sn2—Cu5^iii	4.6859 (12)	Cu2—Cu8^xi	4.8047 (14)
Sn2—Cu5^xx	4.7938 (9)	Cu2—Cu8^xxii	4.8047 (14)
Sn2—Cu5^v	5.1377 (7)	Cu3—Cu3^i	5.5184 (10)
Sn2—Cu5^vi	2.7612 (12)	Cu3—Cu3^ii	4.3326 (4)
Sn2—Cu5^xxi	5.1377 (7)	Cu3—Cu3^iii	4.3326 (4)
Sn2—Cu5^xi	4.6859 (12)	Cu3—Cu3^iv	5.5184 (10)
Sn2—Cu5^xxii	4.6859 (12)	Cu3—Cu3^xxvi	3.9180 (9)
Sn2—Cu5^xv	5.1377 (7)	Cu3—Cu3^xxvii	3.9180 (9)
Sn2—Cu5^xvi	2.7612 (12)	Cu3—Cu3^xxix	3.7320 (9)
Sn2—Cu5^xxiii	5.1377 (7)	Cu3—Cu3^xxviii	3.7320 (9)
Sn2—Cu5^xviii	4.7938 (9)	Cu3—Cu3^xxxix	5.2070 (6)
Sn2—Cu6^xxiv	5.1391 (4)	Cu3—Cu3^xi	2.8881 (9)
Sn2—Cu6^i	2.7639 (2)	Cu3—Cu3^xxii	5.2070 (6)
Sn2—Cu6^xix	5.1391 (4)	Cu3—Cu3^xii	5.0685 (6)
Sn2—Cu6^ii	5.1391 (4)	Cu3—Cu3^xiii	2.6303 (9)
Sn2—Cu6	2.7639 (2)	Cu3—Cu3^xiv	5.0685 (6)
Sn2—Cu6^iii	5.1391 (4)	Cu3—Cu3^xxxii	2.6476 (10)
Sn2—Cu7^i	4.7442 (6)	Cu3—Cu3^xxxiii	2.6476 (10)
Sn2—Cu7^xix	4.7442 (6)	Cu3—Cu4^ii	5.2178 (9)
Sn2—Cu7	2.7113 (5)	Cu3—Cu4	2.9075 (15)
Sn2—Cu7^iii	2.7113 (5)	Cu3—Cu4^iii	5.2178 (9)
Sn2—Cu7^xi	2.7113 (5)	Cu3—Cu4^iv	4.7926 (11)
Sn2—Cu7^xxii	2.7113 (5)	Cu3—Cu4^xxvi	4.8110 (15)
Sn2—Cu7^xiii	4.7442 (6)	Cu3—Cu4^xxvii	4.8110 (15)
Sn2—Cu7^xiv	4.7442 (6)	Cu3—Cu7	4.7821 (17)
Sn2—Cu8^i	4.7884 (8)	Cu3—Cu7^xi	5.5564 (15)
Sn2—Cu8^ii	5.1265 (7)	Cu3—Cu7^xiii	5.4856 (15)
Sn2—Cu8	2.7403 (11)	Cu3—Cu8^ii	3.9172 (14)
Sn2—Cu8^iii	5.1265 (7)	Cu3—Cu8	3.9172 (14)
Sn2—Cu8^xi	5.1265 (7)	Cu3—Cu8^xxvi	5.5469 (15)
Sn2—Cu8^xxii	2.7403 (11)	Cu3—Cu8^xxix	5.5000 (15)
Sn2—Cu8^xxv	5.1265 (7)	Cu3—Cu8^xi	4.8179 (12)
Sn2—Cu8^xiv	4.7884 (8)	Cu3—Cu8^xxii	4.8179 (12)
Sn3—Sn3^i	5.5184 (4)	Cu3—Cu8^xiii	4.7638 (12)
Sn3—Sn3^ii	4.3326 (4)	Cu3—Cu8^xiv	4.7638 (12)
Sn3—Sn3^iii	4.3326 (4)	Cu3—Cu8^xxxiii	4.7855 (17)
Sn3—Sn3^iv	5.5184 (4)	Cu4—Cu4^i	5.5184 (4)
Sn3—Sn3^xxvi	3.8906 (8)	Cu4—Cu4^ii	4.3326 (4)
Sn3—Sn3^xxvii	3.8906 (8)	Cu4—Cu4^iii	4.3326 (4)
Sn3—Sn4^i	3.8459 (4)	Cu4—Cu4^iv	5.5184 (4)
Sn3—Sn4^xix	3.8459 (4)	Cu4—Cu6^xxiv	4.5870 (12)
Sn3—Sn4	3.8459 (4)	Cu4—Cu6^i	4.5870 (12)
Sn3—Sn4^iii	3.8459 (4)	Cu4—Cu6^ii	4.5870 (12)
Sn3—Sn4^xxvii	5.5436 (9)	Cu4—Cu6	4.5870 (12)
Sn3—Sn4^xxviii	5.5436 (9)	Cu4—Cu7^i	4.7092 (10)
Sn3—Cu1^xxiv	5.1384 (4)	Cu4—Cu7^ii	5.0785 (9)
Sn3—Cu1^i	2.7626 (2)	Cu4—Cu7	2.6495 (15)
Sn3—Cu1^xix	5.1384 (4)	Cu4—Cu7^iii	5.0785 (9)
Sn3—Cu1^ii	5.1384 (4)	Cu4—Cu7^xxxix	5.0785 (9)
Sn3—Cu1	2.7626 (2)	Cu4—Cu7^xi	2.6495 (15)
Sn3—Cu1^iii	5.1384 (4)	Cu4—Cu7^xxii	5.0785 (9)
Sn3—Cu1^xxvi	4.6777 (10)	Cu4—Cu7^xiii	4.7092 (10)
Sn3—Cu1^xxvii	4.6777 (10)	Cu4—Cu8^xxiv	4.7449 (6)
Sn3—Cu1^xxix	4.6777 (10)	Cu4—Cu8^i	4.7449 (6)
Sn3—Cu1^xxviii	4.6777 (10)	Cu4—Cu8^ii	2.6635 (6)
Sn3—Cu3^i	4.6929 (7)	Cu4—Cu8	2.6635 (6)
Sn3—Cu3^xix	4.6929 (7)	Cu4—Cu8^xi	2.6635 (6)
Sn3—Cu3	2.7402 (6)	Cu4—Cu8^xxii	2.6635 (6)
Sn3—Cu3^iii	2.7402 (6)	Cu4—Cu8^xiii	4.7449 (6)
Sn3—Cu3^xxvi	5.1484 (7)	Cu4—Cu8^xiv	4.7449 (6)
Sn3—Cu3^xxvii	2.7812 (12)	Cu5—Cu5^i	5.5184 (9)
Sn3—Cu3^xxx	5.1484 (7)	Cu5—Cu5^ii	4.3326 (4)
Sn3—Cu3^xxviii	4.7170 (9)	Cu5—Cu5^iii	4.3326 (4)
Sn3—Cu3^xi	2.7402 (6)	Cu5—Cu5^iv	5.5184 (9)
Sn3—Cu3^xxii	2.7402 (6)	Cu5—Cu5^v	2.6446 (10)
Sn3—Cu3^xiii	4.6929 (7)	Cu5—Cu5^vi	2.6446 (10)
Sn3—Cu3^xiv	4.6929 (7)	Cu5—Cu5^xxxix	5.1493 (6)
Sn3—Cu3^xxxi	4.7170 (9)	Cu5—Cu5^xi	2.7827 (8)
Sn3—Cu3^xxxii	5.1484 (7)	Cu5—Cu5^xxii	5.1493 (6)
Sn3—Cu3^xxxiii	2.7812 (12)	Cu5—Cu5^xii	5.1240 (6)
Sn3—Cu3^xxxiv	5.1484 (7)	Cu5—Cu5^xiii	2.7357 (8)
Sn3—Cu4	2.7345 (9)	Cu5—Cu5^xiv	5.1240 (6)
Sn3—Cu4^iii	2.7345 (9)	Cu5—Cu5^xv	3.8218 (9)
Sn3—Cu4^xxvii	4.9005 (15)	Cu5—Cu5^xvi	3.8218 (9)
Sn3—Cu6^i	5.3848 (13)	Cu5—Cu5^xvii	3.8218 (9)
Sn3—Cu6	5.3848 (13)	Cu5—Cu5^xviii	3.8218 (9)
Sn3—Cu7	4.6940 (11)	Cu5—Cu6^ii	4.8149 (15)
Sn3—Cu7^iii	4.6940 (11)	Cu5—Cu6	4.8149 (15)
Sn3—Cu7^xi	4.6940 (11)	Cu5—Cu6^xl	5.2212 (10)
Sn3—Cu7^xxii	4.6940 (11)	Cu5—Cu6^v	2.9137 (16)
Sn3—Cu8^i	4.8034 (9)	Cu5—Cu6^vi	5.2212 (10)
Sn3—Cu8^ii	5.1405 (7)	Cu5—Cu6^vii	4.8566 (11)
Sn3—Cu8	2.7664 (12)	Cu5—Cu7	4.7740 (17)
Sn3—Cu8^iii	5.1405 (7)	Cu5—Cu7^v	3.9120 (14)
Sn3—Cu8^xi	5.1405 (7)	Cu5—Cu7^vi	3.9120 (14)
Sn3—Cu8^xxii	2.7664 (12)	Cu5—Cu7^xi	5.5231 (15)
Sn3—Cu8^xxv	5.1405 (7)	Cu5—Cu7^xiii	5.5050 (15)
Sn3—Cu8^xiv	4.8034 (9)	Cu5—Cu7^xv	4.7902 (12)
Sn4—Sn4^i	5.5184 (4)	Cu5—Cu7^xvi	4.7902 (12)
Sn4—Sn4^ii	4.3326 (4)	Cu5—Cu7^xvii	4.7840 (12)
Sn4—Sn4^iii	4.3326 (4)	Cu5—Cu7^xviii	4.7840 (12)
Sn4—Sn4^iv	5.5184 (4)	Cu5—Cu8^v	4.7764 (17)
Sn4—Cu1^ii	2.7623 (9)	Cu5—Cu8^xvi	5.5308 (15)
Sn4—Cu1	2.7623 (9)	Cu5—Cu8^xviii	5.5015 (15)
Sn4—Cu1^xxix	4.6707 (15)	Cu6—Cu6^i	5.5184 (4)
Sn4—Cu2	5.6217 (13)	Cu6—Cu6^ii	4.3326 (4)
Sn4—Cu2^iv	5.6217 (13)	Cu6—Cu6^iii	4.3326 (4)
Sn4—Cu3^ii	5.1393 (7)	Cu6—Cu6^iv	5.5184 (4)
Sn4—Cu3	2.7641 (12)	Cu6—Cu7	2.6580 (6)
Sn4—Cu3^iii	5.1393 (7)	Cu6—Cu7^iii	2.6580 (6)
Sn4—Cu3^iv	4.8558 (9)	Cu6—Cu7^iv	4.7288 (6)
Sn4—Cu3^xxix	4.6959 (12)	Cu6—Cu7^x	4.7288 (6)
Sn4—Cu3^xxviii	4.6959 (12)	Cu6—Cu7^xi	4.7288 (6)
Sn4—Cu3^xi	4.8558 (9)	Cu6—Cu7^xxii	4.7288 (6)
Sn4—Cu3^xii	5.1393 (7)	Cu6—Cu7^xiii	2.6580 (6)
Sn4—Cu3^xiii	2.7641 (12)	Cu6—Cu7^xiv	2.6580 (6)
Sn4—Cu3^xiv	5.1393 (7)	Cu6—Cu8^ii	5.0632 (9)
Sn4—Cu3^xxxii	4.6959 (12)	Cu6—Cu8	2.6199 (15)
Sn4—Cu3^xxxiii	4.6959 (12)	Cu6—Cu8^iii	5.0632 (9)
Sn4—Cu4^ii	5.1374 (4)	Cu6—Cu8^iv	4.6794 (10)
Sn4—Cu4	2.7607 (2)	Cu6—Cu8^xxii	4.6794 (10)
Sn4—Cu4^iii	5.1374 (4)	Cu6—Cu8^xiii	5.0632 (9)
Sn4—Cu4^ix	5.1374 (4)	Cu6—Cu8^xiv	2.6199 (15)
Sn4—Cu4^iv	2.7607 (2)	Cu6—Cu8^xxxvii	5.0632 (9)
Sn4—Cu4^x	5.1374 (4)	Cu7—Cu7^i	5.5184 (9)
Sn4—Cu6^ii	3.7392 (12)	Cu7—Cu7^ii	4.3326 (4)
Sn4—Cu6	3.7392 (12)	Cu7—Cu7^iii	4.3326 (4)
Sn4—Cu7^ii	5.1168 (7)	Cu7—Cu7^iv	5.5184 (9)
Sn4—Cu7	2.7222 (12)	Cu7—Cu7^xxxix	5.1434 (6)
Sn4—Cu7^iii	5.1168 (7)	Cu7—Cu7^xi	2.7718 (8)
Sn4—Cu7^iv	4.7652 (9)	Cu7—Cu7^xxii	5.1434 (6)
Sn4—Cu7^xi	4.7652 (9)	Cu7—Cu7^xii	5.1298 (6)
Sn4—Cu7^xii	5.1168 (7)	Cu7—Cu7^xiii	2.7466 (8)
Sn4—Cu7^xiii	2.7222 (12)	Cu7—Cu7^xiv	5.1298 (6)
Sn4—Cu7^xiv	5.1168 (7)	Cu7—Cu8^ii	2.6459 (9)
Sn4—Cu8^ii	2.7085 (5)	Cu7—Cu8	2.6459 (9)
Sn4—Cu8	2.7085 (5)	Cu7—Cu8^xi	3.8147 (9)
Sn4—Cu8^ix	4.7296 (6)	Cu7—Cu8^xxii	3.8147 (9)
Sn4—Cu8^iv	4.7296 (6)	Cu7—Cu8^xiii	3.8309 (9)
Sn4—Cu8^xi	4.7296 (6)	Cu7—Cu8^xiv	3.8309 (9)
Sn4—Cu8^xxii	4.7296 (6)	Cu8—Cu8^i	5.5184 (9)
Sn4—Cu8^xiii	2.7085 (5)	Cu8—Cu8^ii	4.3326 (4)
Sn4—Cu8^xiv	2.7085 (5)	Cu8—Cu8^iii	4.3326 (4)
Cu1—Cu1^i	5.5184 (4)	Cu8—Cu8^iv	5.5184 (9)
Cu1—Cu1^ii	4.3326 (4)	Cu8—Cu8^xi	5.1179 (6)
Cu1—Cu1^iii	4.3326 (4)	Cu8—Cu8^xxii	2.7241 (8)
Cu1—Cu1^iv	5.5184 (4)	Cu8—Cu8^xxv	5.1179 (6)
Cu1—Cu1^xxix	3.6655 (15)	Cu8—Cu8^xiii	5.1555 (6)
Cu1—Cu1^xxviii	3.6655 (15)	Cu8—Cu8^xiv	2.7943 (8)
Cu1—Cu3	2.6338 (6)	Cu8—Cu8^xxxvii	5.1555 (6)

Symmetry codes: (i) x−1, y, z; (ii) x, y, z−1; (iii) x, y, z+1; (iv) x+1, y, z; (v) −x+1/2, −y+1/2, z−1/2; (vi) −x+1/2, −y+1/2, z+1/2; (vii) −x+3/2, −y+1/2, z−1/2; (viii) −x+3/2, −y+1/2, z+1/2; (ix) x+1, y, z−1; (x) x+1, y, z+1; (xi) −x, y, −z+1/2; (xii) −x+1, y, −z−1/2; (xiii) −x+1, y, −z+1/2; (xiv) −x+1, y, −z+3/2; (xv) x−1/2, −y+1/2, −z; (xvi) x−1/2, −y+1/2, −z+1; (xvii) x+1/2, −y+1/2, −z; (xviii) x+1/2, −y+1/2, −z+1; (xix) x−1, y, z+1; (xx) −x−1/2, −y+1/2, z+1/2; (xxi) −x+1/2, −y+1/2, z+3/2; (xxii) −x, y, −z+3/2; (xxiii) x−1/2, −y+1/2, −z+2; (xxiv) x−1, y, z−1; (xxv) −x, y, −z+5/2; (xxvi) −x, −y+1, z−1/2; (xxvii) −x, −y+1, z+1/2; (xxviii) −x+1, −y+1, z+1/2; (xxix) −x+1, −y+1, z−1/2; (xxx) −x, −y+1, z+3/2; (xxxi) x−1, −y+1, −z+1; (xxxii) x, −y+1, −z; (xxxiii) x, −y+1, −z+1; (xxxiv) x, −y+1, −z+2; (xxxv) −x+1, −y+1, z+3/2; (xxxvi) x+1, −y+1, −z+1; (xxxvii) −x+1, y, −z+5/2; (xxxviii) −x−1/2, −y+1/2, z−1/2; (xxxix) −x, y, −z−1/2; (xl) −x+1/2, −y+1/2, z−3/2.

(823K-superstructure)

Crystal data

Cu3Sn	F(000) = 2740
Mr = 309.3	Dx = 8.986 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -C -2x;-2yc;-2zc	Cell parameters from 1970 reflections
a = 5.5199 (1) Å	θ = 4.3–28.2°
b = 47.7904 (9) Å	µ = 37.89 mm^−1
c = 4.3326 (1) Å	T = 293 K
V = 1142.93 (4) Å^3	Trigonal prismatic, metallic grey
Z = 20	0.08 × 0.06 × 0.04 mm

Data collection

Xcalibur, Eos diffractometer	855 independent reflections
Radiation source: Enhance (Mo) X-ray Source	447 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.020
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.4°, θmin = 3.4°
ω and π scans	h = −7→6
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −59→61
Tmin = 0.15, Tmax = 0.281	l = −5→5
8648 measured reflections

Refinement

Refinement on F^2	0 constraints
R[F^2 > 2σ(F^2)] = 0.023	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.088	(Δ/σ)max = 0.034
S = 1.71	Δρmax = 1.35 e Å^−3
855 reflections	Δρmin = −1.20 e Å^−3
72 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 255 (11)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0	0.23386 (2)	0.25	0.0090 (3)
Sn2	0	0.13385 (2)	0.25	0.0104 (3)
Sn3	0.5	0.06676 (2)	0.75	0.0110 (3)
Sn4	0.5	0.16631 (2)	0.75	0.0107 (3)
Sn5	0	0.03375 (2)	0.25	0.0108 (3)
Cu1	0	0.16917 (4)	0.75	0.0135 (6)
Cu2	0.5	0.03086 (4)	0.25	0.0142 (6)
Cu3	0	0.06864 (4)	0.75	0.0152 (6)
Cu4	0.25197 (15)	0.21601 (4)	0.75	0.0123 (6)
Cu5	0.24740 (16)	0.18434 (3)	0.25	0.0145 (6)
Cu6	0.25113 (15)	0.11617 (4)	0.75	0.0154 (6)
Cu7	0.24664 (15)	0.08415 (3)	0.25	0.0126 (6)
Cu8	0.26147 (17)	0.01599 (4)	0.75	0.0121 (5)
Cu9	0.5	0.13038 (4)	0.25	0.0124 (6)
Cu10	0.5	0.23075 (4)	0.25	0.0120 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0089 (6)	0.0096 (5)	0.0084 (6)	0	0	0
Sn2	0.0103 (6)	0.0114 (5)	0.0095 (6)	0	0	0
Sn3	0.0120 (6)	0.0098 (5)	0.0113 (6)	0	0	0
Sn4	0.0110 (6)	0.0102 (5)	0.0109 (6)	0	0	0
Sn5	0.0115 (6)	0.0098 (5)	0.0110 (6)	0	0	0
Cu1	0.0131 (11)	0.0153 (10)	0.0122 (11)	0	0	0
Cu2	0.0145 (11)	0.0152 (10)	0.0128 (11)	0	0	0
Cu3	0.0154 (11)	0.0166 (9)	0.0136 (12)	0	0	0
Cu4	0.0138 (10)	0.0128 (9)	0.0102 (10)	−0.0002 (3)	0	0
Cu5	0.0184 (11)	0.0143 (10)	0.0109 (11)	−0.0001 (3)	0	0
Cu6	0.0185 (12)	0.0141 (9)	0.0135 (11)	0.0005 (4)	0	0
Cu7	0.0153 (12)	0.0117 (9)	0.0110 (11)	−0.0004 (3)	0	0
Cu8	0.0140 (10)	0.0108 (8)	0.0113 (10)	−0.0014 (3)	0	0
Cu9	0.0114 (11)	0.0148 (10)	0.0111 (11)	0	0	0
Cu10	0.0101 (10)	0.0165 (10)	0.0096 (10)	0	0	0

Bond lengths (Å)

Sn1—Sn1^i	5.5199 (2)	Cu1—Cu1^iii	4.3326 (2)
Sn1—Sn1^ii	4.3326 (2)	Cu1—Cu1^iv	5.5199 (2)
Sn1—Sn1^iii	4.3326 (2)	Cu1—Cu3	4.805 (3)
Sn1—Sn1^iv	5.5199 (2)	Cu1—Cu4^i	4.6969 (14)
Sn1—Sn1^v	3.8329 (6)	Cu1—Cu4^ii	5.0713 (12)
Sn1—Sn1^vi	3.8329 (6)	Cu1—Cu4	2.636 (2)
Sn1—Sn1^vii	3.8329 (6)	Cu1—Cu4^iii	5.0713 (12)
Sn1—Sn1^viii	3.8329 (6)	Cu1—Cu4^xi	5.0713 (12)
Sn1—Sn2	4.7796 (15)	Cu1—Cu4^xii	2.636 (2)
Sn1—Sn4^ix	4.7678 (10)	Cu1—Cu4^xxxiv	5.0713 (12)
Sn1—Sn4^i	4.7678 (10)	Cu1—Cu4^xiv	4.6969 (14)
Sn1—Sn4^ii	4.7678 (10)	Cu1—Cu5^i	4.7410 (8)
Sn1—Sn4	4.7678 (10)	Cu1—Cu5^xx	4.7410 (8)
Sn1—Sn4^vii	4.7712 (14)	Cu1—Cu5	2.6615 (8)
Sn1—Cu1^ii	3.7749 (18)	Cu1—Cu5^iii	2.6615 (8)
Sn1—Cu1	3.7749 (18)	Cu1—Cu5^xi	2.6615 (8)
Sn1—Cu1^v	5.3940 (18)	Cu1—Cu5^xii	2.6615 (8)
Sn1—Cu1^vii	5.3940 (18)	Cu1—Cu5^xiii	4.7410 (8)
Sn1—Cu4^ix	4.7402 (8)	Cu1—Cu5^xiv	4.7410 (8)
Sn1—Cu4^i	4.7402 (8)	Cu1—Cu6^i	4.8479 (15)
Sn1—Cu4^ii	2.7119 (8)	Cu1—Cu6^ii	5.2065 (13)
Sn1—Cu4	2.7119 (8)	Cu1—Cu6	2.887 (2)
Sn1—Cu4^v	4.7925 (12)	Cu1—Cu6^iii	5.2065 (13)
Sn1—Cu4^x	5.1367 (10)	Cu1—Cu6^xi	5.2065 (13)
Sn1—Cu4^vii	2.7594 (18)	Cu1—Cu6^xii	2.887 (2)
Sn1—Cu4^viii	5.1367 (10)	Cu1—Cu6^xxxiv	5.2065 (13)
Sn1—Cu4^xi	2.7119 (8)	Cu1—Cu6^xiv	4.8479 (15)
Sn1—Cu4^xii	2.7119 (8)	Cu1—Cu7	4.802 (2)
Sn1—Cu4^xiii	4.7402 (8)	Cu1—Cu7^iii	4.802 (2)
Sn1—Cu4^xiv	4.7402 (8)	Cu1—Cu7^xi	4.802 (2)
Sn1—Cu4^xv	5.1367 (10)	Cu1—Cu7^xii	4.802 (2)
Sn1—Cu4^xvi	2.7594 (18)	Cu1—Cu9^i	3.9682 (12)
Sn1—Cu4^xvii	5.1367 (10)	Cu1—Cu9^xx	3.9682 (12)
Sn1—Cu4^xviii	4.7925 (12)	Cu1—Cu9	3.9682 (12)
Sn1—Cu5^i	4.7809 (12)	Cu1—Cu9^iii	3.9682 (12)
Sn1—Cu5^ii	5.1221 (9)	Cu1—Cu10^i	4.5794 (17)
Sn1—Cu5	2.7320 (17)	Cu1—Cu10^xx	4.5794 (17)
Sn1—Cu5^iii	5.1221 (9)	Cu1—Cu10	4.5794 (17)
Sn1—Cu5^vii	4.6818 (16)	Cu1—Cu10^iii	4.5794 (17)
Sn1—Cu5^viii	4.6818 (16)	Cu1—Cu10^viii	4.783 (3)
Sn1—Cu5^xix	5.1221 (9)	Cu2—Cu2^i	5.5199 (2)
Sn1—Cu5^xi	2.7320 (17)	Cu2—Cu2^ii	4.3326 (2)
Sn1—Cu5^xii	5.1221 (9)	Cu2—Cu2^iii	4.3326 (2)
Sn1—Cu5^xiii	4.7809 (12)	Cu2—Cu2^iv	5.5199 (2)
Sn1—Cu5^xv	4.6818 (16)	Cu2—Cu2^xxvi	3.659 (2)
Sn1—Cu5^xvi	4.6818 (16)	Cu2—Cu2^xxiii	3.659 (2)
Sn1—Cu9^i	5.6633 (18)	Cu2—Cu3^ii	3.9459 (13)
Sn1—Cu9	5.6633 (18)	Cu2—Cu3	3.9459 (13)
Sn1—Cu10^ix	5.1391 (2)	Cu2—Cu3^xxiv	3.9459 (13)
Sn1—Cu10^i	2.7639 (1)	Cu2—Cu3^iv	3.9459 (13)
Sn1—Cu10^xx	5.1391 (2)	Cu2—Cu3^xxx	5.498 (2)
Sn1—Cu10^ii	5.1391 (2)	Cu2—Cu3^xxvi	5.498 (2)
Sn1—Cu10	2.7639 (1)	Cu2—Cu6^ii	4.817 (2)
Sn1—Cu10^iii	5.1391 (2)	Cu2—Cu6	4.817 (2)
Sn1—Cu10^vii	2.7484 (13)	Cu2—Cu6^xiii	4.817 (2)
Sn1—Cu10^viii	2.7484 (13)	Cu2—Cu6^xiv	4.817 (2)
Sn2—Sn2^i	5.5199 (2)	Cu2—Cu7^ii	5.2167 (13)
Sn2—Sn2^ii	4.3326 (2)	Cu2—Cu7	2.906 (2)
Sn2—Sn2^iii	4.3326 (2)	Cu2—Cu7^iii	5.2167 (13)
Sn2—Sn2^iv	5.5199 (2)	Cu2—Cu7^iv	4.8448 (15)
Sn2—Sn3^ix	4.7528 (10)	Cu2—Cu7^xi	4.8448 (15)
Sn2—Sn3^i	4.7528 (10)	Cu2—Cu7^xxxv	5.2167 (13)
Sn2—Sn3^ii	4.7528 (10)	Cu2—Cu7^xiii	2.906 (2)
Sn2—Sn3	4.7528 (10)	Cu2—Cu7^xiv	5.2167 (13)
Sn2—Sn4^ix	3.8362 (6)	Cu2—Cu8^ii	2.6328 (9)
Sn2—Sn4^i	3.8362 (6)	Cu2—Cu8	2.6328 (9)
Sn2—Sn4^ii	3.8362 (6)	Cu2—Cu8^xxiv	4.7817 (9)
Sn2—Sn4	3.8362 (6)	Cu2—Cu8^iv	4.7817 (9)
Sn2—Sn5	4.7838 (15)	Cu2—Cu8^xxx	4.7622 (15)
Sn2—Cu1^ii	2.7464 (13)	Cu2—Cu8^xxxvi	5.0514 (12)
Sn2—Cu1	2.7464 (13)	Cu2—Cu8^xxvi	2.597 (2)
Sn2—Cu2^i	5.643 (2)	Cu2—Cu8^xxiii	5.0514 (12)
Sn2—Cu2	5.643 (2)	Cu2—Cu8^xi	4.7817 (9)
Sn2—Cu3^ii	3.7954 (19)	Cu2—Cu8^xii	4.7817 (9)
Sn2—Cu3	3.7954 (19)	Cu2—Cu8^xiii	2.6328 (9)
Sn2—Cu4^ii	4.6954 (17)	Cu2—Cu8^xiv	2.6328 (9)
Sn2—Cu4	4.6954 (17)	Cu2—Cu8^xxxiii	5.0514 (12)
Sn2—Cu4^xi	4.6954 (17)	Cu2—Cu8^xxvii	2.597 (2)
Sn2—Cu4^xii	4.6954 (17)	Cu2—Cu8^xxviii	5.0514 (12)
Sn2—Cu5^i	4.8044 (12)	Cu2—Cu8^xxxvii	4.7622 (15)
Sn2—Cu5^ii	5.1440 (9)	Cu2—Cu9	4.756 (3)
Sn2—Cu5	2.7729 (17)	Cu3—Cu3^i	5.5199 (2)
Sn2—Cu5^iii	5.1440 (9)	Cu3—Cu3^ii	4.3326 (2)
Sn2—Cu5^xix	5.1440 (9)	Cu3—Cu3^iii	4.3326 (2)
Sn2—Cu5^xi	2.7729 (17)	Cu3—Cu3^iv	5.5199 (2)
Sn2—Cu5^xii	5.1440 (9)	Cu3—Cu6^i	4.7168 (15)
Sn2—Cu5^xiii	4.8044 (12)	Cu3—Cu6^ii	5.0847 (12)
Sn2—Cu6^ix	4.7427 (8)	Cu3—Cu6	2.661 (2)
Sn2—Cu6^i	4.7427 (8)	Cu3—Cu6^iii	5.0847 (12)
Sn2—Cu6^ii	2.7070 (8)	Cu3—Cu6^xi	5.0847 (12)
Sn2—Cu6	2.7070 (8)	Cu3—Cu6^xii	2.661 (2)
Sn2—Cu6^xi	2.7070 (8)	Cu3—Cu6^xxxiv	5.0847 (12)
Sn2—Cu6^xii	2.7070 (8)	Cu3—Cu6^xiv	4.7168 (15)
Sn2—Cu6^xiii	4.7427 (8)	Cu3—Cu7^i	4.7472 (8)
Sn2—Cu6^xiv	4.7427 (8)	Cu3—Cu7^xx	4.7472 (8)
Sn2—Cu7^i	4.7890 (12)	Cu3—Cu7	2.6638 (8)
Sn2—Cu7^ii	5.1250 (9)	Cu3—Cu7^iii	2.6638 (8)
Sn2—Cu7	2.7376 (17)	Cu3—Cu7^xi	2.6638 (8)
Sn2—Cu7^iii	5.1250 (9)	Cu3—Cu7^xii	2.6638 (8)
Sn2—Cu7^xix	5.1250 (9)	Cu3—Cu7^xiii	4.7472 (8)
Sn2—Cu7^xi	2.7376 (17)	Cu3—Cu7^xiv	4.7472 (8)
Sn2—Cu7^xii	5.1250 (9)	Cu3—Cu8^i	4.7906 (16)
Sn2—Cu7^xiii	4.7890 (12)	Cu3—Cu8^ii	5.2139 (13)
Sn2—Cu9^ix	5.1397 (2)	Cu3—Cu8	2.901 (2)
Sn2—Cu9^i	2.7649 (2)	Cu3—Cu8^iii	5.2139 (13)
Sn2—Cu9^xx	5.1397 (2)	Cu3—Cu8^xxx	4.809 (2)
Sn2—Cu9^ii	5.1397 (2)	Cu3—Cu8^xxii	4.809 (2)
Sn2—Cu9	2.7649 (2)	Cu3—Cu8^xi	5.2139 (13)
Sn2—Cu9^iii	5.1397 (2)	Cu3—Cu8^xii	2.901 (2)
Sn2—Cu10^i	5.3911 (19)	Cu3—Cu8^xxxiv	5.2139 (13)
Sn2—Cu10	5.3911 (19)	Cu3—Cu8^xiv	4.7906 (16)
Sn3—Sn3^i	5.5199 (2)	Cu3—Cu8^xxvii	4.809 (2)
Sn3—Sn3^ii	4.3326 (2)	Cu3—Cu8^xxviii	4.809 (2)
Sn3—Sn3^iii	4.3326 (2)	Cu3—Cu9^i	4.5844 (17)
Sn3—Sn3^iv	5.5199 (2)	Cu3—Cu9^xx	4.5844 (17)
Sn3—Sn4	4.7573 (14)	Cu3—Cu9	4.5844 (17)
Sn3—Sn5	3.8470 (6)	Cu3—Cu9^iii	4.5844 (17)
Sn3—Sn5^iii	3.8470 (6)	Cu4—Cu4^i	5.5199 (12)
Sn3—Sn5^iv	3.8470 (6)	Cu4—Cu4^ii	4.3326 (2)
Sn3—Sn5^xxi	3.8470 (6)	Cu4—Cu4^iii	4.3326 (2)
Sn3—Sn5^xxii	5.5397 (13)	Cu4—Cu4^iv	5.5199 (12)
Sn3—Sn5^xxiii	5.5397 (13)	Cu4—Cu4^vii	3.905 (2)
Sn3—Cu1	5.6187 (19)	Cu4—Cu4^viii	3.905 (2)
Sn3—Cu1^iv	5.6187 (19)	Cu4—Cu4^xi	5.1487 (7)
Sn3—Cu2	2.7636 (14)	Cu4—Cu4^xii	2.7817 (12)
Sn3—Cu2^iii	2.7636 (14)	Cu4—Cu4^xxxiv	5.1487 (7)
Sn3—Cu2^xxiii	4.665 (2)	Cu4—Cu4^xiii	5.1254 (6)
Sn3—Cu3^ii	5.1378 (2)	Cu4—Cu4^xiv	2.7382 (12)
Sn3—Cu3	2.7614 (1)	Cu4—Cu4^xxv	5.1254 (6)
Sn3—Cu3^iii	5.1378 (2)	Cu4—Cu4^xvi	4.7815 (18)
Sn3—Cu3^xxiv	5.1378 (2)	Cu4—Cu4^xvii	4.7815 (18)
Sn3—Cu3^iv	2.7614 (1)	Cu4—Cu4^xviii	4.7815 (18)
Sn3—Cu3^xxi	5.1378 (2)	Cu4—Cu4^xxxviii	4.7815 (18)
Sn3—Cu6^ii	5.1220 (10)	Cu4—Cu5	2.6427 (13)
Sn3—Cu6	2.7319 (18)	Cu4—Cu5^iii	2.6427 (13)
Sn3—Cu6^iii	5.1220 (10)	Cu4—Cu5^viii	4.762 (2)
Sn3—Cu6^iv	4.7715 (12)	Cu4—Cu5^xi	3.8186 (13)
Sn3—Cu6^xii	4.7715 (12)	Cu4—Cu5^xii	3.8186 (13)
Sn3—Cu6^xiii	5.1220 (10)	Cu4—Cu5^xiii	3.8236 (13)
Sn3—Cu6^xiv	2.7319 (18)	Cu4—Cu5^xiv	3.8236 (13)
Sn3—Cu6^xxv	5.1220 (10)	Cu4—Cu5^xvi	5.517 (2)
Sn3—Cu7	2.7091 (7)	Cu4—Cu5^xviii	5.491 (2)
Sn3—Cu7^iii	2.7091 (7)	Cu4—Cu6	4.771 (2)
Sn3—Cu7^iv	4.7296 (8)	Cu4—Cu6^xii	5.521 (2)
Sn3—Cu7^xxi	4.7296 (8)	Cu4—Cu6^xiv	5.504 (2)
Sn3—Cu7^xi	4.7296 (8)	Cu4—Cu9	4.829 (2)
Sn3—Cu7^xii	4.7296 (8)	Cu4—Cu9^iii	4.829 (2)
Sn3—Cu7^xiii	2.7091 (7)	Cu4—Cu10^i	4.7348 (8)
Sn3—Cu7^xiv	2.7091 (7)	Cu4—Cu10^xx	4.7348 (8)
Sn3—Cu8^ii	5.1374 (10)	Cu4—Cu10	2.6577 (8)
Sn3—Cu8	2.7607 (18)	Cu4—Cu10^iii	2.6577 (8)
Sn3—Cu8^iii	5.1374 (10)	Cu4—Cu10^vii	5.2133 (13)
Sn3—Cu8^iv	4.8534 (13)	Cu4—Cu10^viii	2.900 (2)
Sn3—Cu8^xxvi	4.6973 (17)	Cu4—Cu10^xxxix	5.2133 (13)
Sn3—Cu8^xxiii	4.6973 (17)	Cu4—Cu10^xxix	4.8500 (15)
Sn3—Cu8^xii	4.8534 (13)	Cu5—Cu5^i	5.5199 (12)
Sn3—Cu8^xiii	5.1374 (10)	Cu5—Cu5^ii	4.3326 (2)
Sn3—Cu8^xiv	2.7607 (18)	Cu5—Cu5^iii	4.3326 (2)
Sn3—Cu8^xxv	5.1374 (10)	Cu5—Cu5^iv	5.5199 (12)
Sn3—Cu8^xxvii	4.6973 (17)	Cu5—Cu5^xix	5.1216 (7)
Sn3—Cu8^xxviii	4.6973 (17)	Cu5—Cu5^xi	2.7313 (12)
Sn3—Cu9	3.7331 (17)	Cu5—Cu5^xii	5.1216 (7)
Sn3—Cu9^iii	3.7331 (17)	Cu5—Cu5^xxxv	5.1525 (7)
Sn4—Sn4^i	5.5199 (2)	Cu5—Cu5^xiii	2.7886 (12)
Sn4—Sn4^ii	4.3326 (2)	Cu5—Cu5^xiv	5.1525 (7)
Sn4—Sn4^iii	4.3326 (2)	Cu5—Cu6^ii	3.9125 (19)
Sn4—Sn4^iv	5.5199 (2)	Cu5—Cu6	3.9125 (19)
Sn4—Cu1^ii	5.1388 (2)	Cu5—Cu6^xi	4.7833 (17)
Sn4—Cu1	2.7633 (1)	Cu5—Cu6^xii	4.7833 (17)
Sn4—Cu1^iii	5.1388 (2)	Cu5—Cu6^xiii	4.7926 (17)
Sn4—Cu1^xxiv	5.1388 (2)	Cu5—Cu6^xiv	4.7926 (17)
Sn4—Cu1^iv	2.7633 (1)	Cu5—Cu7	4.788 (2)
Sn4—Cu1^xxi	5.1388 (2)	Cu5—Cu7^xi	5.510 (2)
Sn4—Cu3	5.4226 (19)	Cu5—Cu7^xiii	5.543 (2)
Sn4—Cu3^iv	5.4226 (19)	Cu5—Cu9^i	4.8654 (15)
Sn4—Cu4^ii	5.1273 (10)	Cu5—Cu9^ii	5.2314 (12)
Sn4—Cu4	2.7418 (18)	Cu5—Cu9	2.932 (2)
Sn4—Cu4^iii	5.1273 (10)	Cu5—Cu9^iii	5.2314 (12)
Sn4—Cu4^iv	4.7825 (12)	Cu5—Cu10^i	4.6839 (14)
Sn4—Cu4^xii	4.7825 (12)	Cu5—Cu10^ii	5.0630 (11)
Sn4—Cu4^xiii	5.1273 (10)	Cu5—Cu10	2.620 (2)
Sn4—Cu4^xiv	2.7418 (18)	Cu5—Cu10^iii	5.0630 (11)
Sn4—Cu4^xxv	5.1273 (10)	Cu5—Cu10^vii	4.798 (2)
Sn4—Cu5	2.7166 (7)	Cu5—Cu10^viii	4.798 (2)
Sn4—Cu5^iii	2.7166 (7)	Cu6—Cu6^i	5.5199 (12)
Sn4—Cu5^iv	4.7388 (8)	Cu6—Cu6^ii	4.3326 (2)
Sn4—Cu5^xxi	4.7388 (8)	Cu6—Cu6^iii	4.3326 (2)
Sn4—Cu5^xi	4.7388 (8)	Cu6—Cu6^iv	5.5199 (12)
Sn4—Cu5^xii	4.7388 (8)	Cu6—Cu6^xi	5.1437 (7)
Sn4—Cu5^xiii	2.7166 (7)	Cu6—Cu6^xii	2.7725 (12)
Sn4—Cu5^xiv	2.7166 (7)	Cu6—Cu6^xxxiv	5.1437 (7)
Sn4—Cu6^ii	5.1380 (10)	Cu6—Cu6^xiii	5.1303 (7)
Sn4—Cu6	2.7618 (18)	Cu6—Cu6^xiv	2.7474 (12)
Sn4—Cu6^iii	5.1380 (10)	Cu6—Cu6^xxv	5.1303 (7)
Sn4—Cu6^iv	4.7887 (12)	Cu6—Cu7	2.6525 (13)
Sn4—Cu6^xii	4.7887 (12)	Cu6—Cu7^iii	2.6525 (13)
Sn4—Cu6^xiii	5.1380 (10)	Cu6—Cu7^xi	3.8190 (13)
Sn4—Cu6^xiv	2.7618 (18)	Cu6—Cu7^xii	3.8190 (13)
Sn4—Cu6^xxv	5.1380 (10)	Cu6—Cu7^xiii	3.8367 (13)
Sn4—Cu7	4.6974 (16)	Cu6—Cu7^xiv	3.8367 (13)
Sn4—Cu7^iii	4.6974 (16)	Cu6—Cu8	4.788 (2)
Sn4—Cu7^xiii	4.6974 (16)	Cu6—Cu8^xii	5.561 (2)
Sn4—Cu7^xiv	4.6974 (16)	Cu6—Cu8^xiv	5.492 (2)
Sn4—Cu9	2.7642 (13)	Cu6—Cu9^i	4.7270 (8)
Sn4—Cu9^iii	2.7642 (13)	Cu6—Cu9^xx	4.7270 (8)
Sn4—Cu10	3.7654 (18)	Cu6—Cu9	2.6535 (8)
Sn4—Cu10^iii	3.7654 (18)	Cu6—Cu9^iii	2.6535 (8)
Sn4—Cu10^viii	5.6410 (19)	Cu7—Cu7^i	5.5199 (12)
Sn4—Cu10^xxix	5.6410 (19)	Cu7—Cu7^ii	4.3326 (2)
Sn5—Sn5^i	5.5199 (2)	Cu7—Cu7^iii	4.3326 (2)
Sn5—Sn5^ii	4.3326 (2)	Cu7—Cu7^iv	5.5199 (12)
Sn5—Sn5^iii	4.3326 (2)	Cu7—Cu7^xix	5.1171 (6)
Sn5—Sn5^iv	5.5199 (2)	Cu7—Cu7^xi	2.7228 (12)
Sn5—Sn5^xxx	3.8854 (12)	Cu7—Cu7^xii	5.1171 (6)
Sn5—Sn5^xxii	3.8854 (12)	Cu7—Cu7^xxxv	5.1570 (6)
Sn5—Cu2^ix	5.1389 (2)	Cu7—Cu7^xiii	2.7971 (12)
Sn5—Cu2^i	2.7634 (1)	Cu7—Cu7^xiv	5.1570 (6)
Sn5—Cu2^xx	5.1389 (2)	Cu7—Cu8^ii	3.913 (2)
Sn5—Cu2^ii	5.1389 (2)	Cu7—Cu8	3.913 (2)
Sn5—Cu2	2.7634 (1)	Cu7—Cu8^xxx	5.547 (2)
Sn5—Cu2^iii	5.1389 (2)	Cu7—Cu8^xxvi	5.502 (2)
Sn5—Cu2^xxx	4.6735 (15)	Cu7—Cu8^xi	4.8135 (18)
Sn5—Cu2^xxii	4.6735 (15)	Cu7—Cu8^xii	4.8135 (18)
Sn5—Cu2^xxvi	4.6735 (15)	Cu7—Cu8^xiii	4.7620 (18)
Sn5—Cu2^xxiii	4.6735 (15)	Cu7—Cu8^xiv	4.7620 (18)
Sn5—Cu3^ii	2.7337 (14)	Cu7—Cu8^xxvii	4.786 (2)
Sn5—Cu3	2.7337 (14)	Cu7—Cu9^i	4.6762 (13)
Sn5—Cu3^xxx	4.893 (2)	Cu7—Cu9^ii	5.0605 (11)
Sn5—Cu6^ii	4.7044 (17)	Cu7—Cu9	2.615 (2)
Sn5—Cu6	4.7044 (17)	Cu7—Cu9^iii	5.0605 (11)
Sn5—Cu6^xi	4.7044 (17)	Cu8—Cu8^i	5.5199 (13)
Sn5—Cu6^xii	4.7044 (17)	Cu8—Cu8^ii	4.3326 (2)
Sn5—Cu7^i	4.8057 (12)	Cu8—Cu8^iii	4.3326 (2)
Sn5—Cu7^ii	5.1407 (9)	Cu8—Cu8^iv	5.5199 (13)
Sn5—Cu7	2.7668 (17)	Cu8—Cu8^xxx	3.9192 (14)
Sn5—Cu7^iii	5.1407 (9)	Cu8—Cu8^xxii	3.9192 (14)
Sn5—Cu7^xix	5.1407 (9)	Cu8—Cu8^xxvi	3.7366 (14)
Sn5—Cu7^xi	2.7668 (17)	Cu8—Cu8^xxiii	3.7366 (14)
Sn5—Cu7^xii	5.1407 (9)	Cu8—Cu8^xi	5.2061 (7)
Sn5—Cu7^xiii	4.8057 (12)	Cu8—Cu8^xii	2.8865 (13)
Sn5—Cu8^ix	4.6938 (9)	Cu8—Cu8^xxxiv	5.2061 (7)
Sn5—Cu8^i	4.6938 (9)	Cu8—Cu8^xiii	5.0701 (7)
Sn5—Cu8^ii	2.7379 (8)	Cu8—Cu8^xiv	2.6334 (13)
Sn5—Cu8	2.7379 (8)	Cu8—Cu8^xxv	5.0701 (7)
Sn5—Cu8^xxxi	5.1481 (10)	Cu8—Cu8^xxvii	2.6510 (14)
Sn5—Cu8^xxx	2.7807 (18)	Cu8—Cu8^xxviii	2.6510 (14)
Sn5—Cu8^xxii	5.1481 (10)	Cu9—Cu9^i	5.5199 (2)
Sn5—Cu8^xxvi	4.7189 (13)	Cu9—Cu9^ii	4.3326 (2)
Sn5—Cu8^xi	2.7379 (8)	Cu9—Cu9^iii	4.3326 (2)
Sn5—Cu8^xii	2.7379 (8)	Cu9—Cu9^iv	5.5199 (2)
Sn5—Cu8^xiii	4.6938 (9)	Cu9—Cu10	4.797 (3)
Sn5—Cu8^xiv	4.6938 (9)	Cu10—Cu10^i	5.5199 (2)
Sn5—Cu8^xxxii	4.7189 (13)	Cu10—Cu10^ii	4.3326 (2)
Sn5—Cu8^xxxiii	5.1481 (10)	Cu10—Cu10^iii	4.3326 (2)
Sn5—Cu8^xxvii	2.7807 (18)	Cu10—Cu10^iv	5.5199 (2)
Sn5—Cu8^xxviii	5.1481 (10)	Cu10—Cu10^vii	3.9618 (13)
Sn5—Cu9^i	5.3800 (18)	Cu10—Cu10^viii	3.9618 (13)
Sn5—Cu9	5.3800 (18)	Cu10—Cu10^xl	3.9618 (13)
Cu1—Cu1^i	5.5199 (2)	Cu10—Cu10^xxix	3.9618 (13)
Cu1—Cu1^ii	4.3326 (2)

Symmetry codes: (i) x−1, y, z; (ii) x, y, z−1; (iii) x, y, z+1; (iv) x+1, y, z; (v) −x−1/2, −y+1/2, z−1/2; (vi) −x−1/2, −y+1/2, z+1/2; (vii) −x+1/2, −y+1/2, z−1/2; (viii) −x+1/2, −y+1/2, z+1/2; (ix) x−1, y, z−1; (x) −x+1/2, −y+1/2, z−3/2; (xi) −x, y, −z+1/2; (xii) −x, y, −z+3/2; (xiii) −x+1, y, −z+1/2; (xiv) −x+1, y, −z+3/2; (xv) x−1/2, −y+1/2, −z; (xvi) x−1/2, −y+1/2, −z+1; (xvii) x−1/2, −y+1/2, −z+2; (xviii) x+1/2, −y+1/2, −z+1; (xix) −x, y, −z−1/2; (xx) x−1, y, z+1; (xxi) x+1, y, z+1; (xxii) −x, −y, z+1/2; (xxiii) −x+1, −y, z+1/2; (xxiv) x+1, y, z−1; (xxv) −x+1, y, −z+5/2; (xxvi) −x+1, −y, z−1/2; (xxvii) x, −y, −z+1; (xxviii) x, −y, −z+2; (xxix) −x+3/2, −y+1/2, z+1/2; (xxx) −x, −y, z−1/2; (xxxi) −x, −y, z−3/2; (xxxii) x−1, −y, −z+1; (xxxiii) x, −y, −z; (xxxiv) −x, y, −z+5/2; (xxxv) −x+1, y, −z−1/2; (xxxvi) −x+1, −y, z−3/2; (xxxvii) x+1, −y, −z+1; (xxxviii) x+1/2, −y+1/2, −z+2; (xxxix) −x+1/2, −y+1/2, z+3/2; (xl) −x+3/2, −y+1/2, z−1/2.

(473K-modulated)

Crystal data

Cu3.048Sn0.952	F(000) = 272
Mr = 306.7	Dx = 8.875 Mg m^−3
Orthorhombic, Xmcm(0β0)000†	Mo Kα radiation, λ = 0.71073 Å
q = 0.094900b*	Cell parameters from 776 reflections
a = 5.528 (2) Å	θ = 5.3–27.6°
b = 4.783 (4) Å	µ = 37.66 mm^−1
c = 4.3391 (18) Å	T = 293 K
V = 114.73 (11) Å^3	Trigonal prismatic, metallic dark grey
Z = 2	0.24 × 0.05 × 0.03 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, x₂, x₃, x₄; (3) x₁, x₂, −x₃, x₄; (4) −x₁, −x₂+2/3, −x₃+1/2, −x₄; (5) −x₁, x₂, −x₃, x₄; (6) x₁, −x₂+2/3, −x₃+1/2, −x₄; (7) −x₁, −x₂+2/3, x₃+1/2, −x₄; (8) x₁, −x₂+2/3, x₃+1/2, −x₄; (9) x₁+1/2, x₂, x₃, x₄+1/2; (10) −x₁+1/2, x₂, x₃, x₄+1/2; (11) x₁+1/2, x₂, −x₃, x₄+1/2; (12) −x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (13) −x₁+1/2, x₂, −x₃, x₄+1/2; (14) x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (15) −x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2; (16) x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2.

Data collection

Xcalibur, Eos diffractometer	591 independent reflections
Radiation source: X-ray tube	276 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.4°, θmin = 3.5°
ω scans	h = −7→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −6→6
Tmin = 0.148, Tmax = 0.474	l = −5→5
4102 measured reflections

Refinement

Refinement on F^2	12 constraints
R[F^2 > 2σ(F^2)] = 0.035	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.103	(Δ/σ)max = 0.045
S = 1.34	Δρmax = 2.84 e Å^−3
591 reflections	Δρmin = −3.75 e Å^−3
24 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 111 (8)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Sn1	0	0.65651 (15)	0	0.0097 (2)	0.476 (3)
Cu1	0	0.65651 (15)	0	0.0097 (2)	0.524 (3)
Cu2	−0.25	0.49256 (19)	0.5	0.0127 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0093 (4)	0.0104 (4)	0.0093 (4)	0	0	0
Cu1	0.0093 (4)	0.0104 (4)	0.0093 (4)	0	0	0
Cu2	0.0150 (6)	0.0120 (5)	0.0110 (6)	0	0	0

(573K-modulated)

Crystal data

Cu3.027Sn0.973	F(000) = 273
Mr = 307.9	Dx = 8.919 Mg m^−3
Orthorhombic, Xmcm(0β0)000†	Mo Kα radiation, λ = 0.71073 Å
q = 0.101400b*	Cell parameters from 1434 reflections
a = 5.525 (2) Å	θ = 4.2–27.6°
b = 4.781 (3) Å	µ = 37.74 mm^−1
c = 4.3385 (17) Å	T = 293 K
V = 114.60 (9) Å^3	Trigonal prismatic, metallic dark grey
Z = 2	0.09 × 0.05 × 0.02 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, x₂, x₃, x₄; (3) x₁, x₂, −x₃, x₄; (4) −x₁, −x₂+2/3, −x₃+1/2, −x₄; (5) −x₁, x₂, −x₃, x₄; (6) x₁, −x₂+2/3, −x₃+1/2, −x₄; (7) −x₁, −x₂+2/3, x₃+1/2, −x₄; (8) x₁, −x₂+2/3, x₃+1/2, −x₄; (9) x₁+1/2, x₂, x₃, x₄+1/2; (10) −x₁+1/2, x₂, x₃, x₄+1/2; (11) x₁+1/2, x₂, −x₃, x₄+1/2; (12) −x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (13) −x₁+1/2, x₂, −x₃, x₄+1/2; (14) x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (15) −x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2; (16) x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2.

Data collection

Xcalibur, Eos diffractometer	919 independent reflections
Radiation source: X-ray tube	406 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.1°, θmin = 3.4°
ω scans	h = −6→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −6→6
Tmin = 0.15, Tmax = 0.51	l = −5→5
9022 measured reflections

Refinement

Refinement on F^2	16 constraints
R[F^2 > 2σ(F^2)] = 0.038	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.112	(Δ/σ)max = 0.033
S = 1.52	Δρmax = 3.07 e Å^−3
919 reflections	Δρmin = −3.48 e Å^−3
32 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 272 (10)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Sn1	0	0.51022 (12)	0	0.00911 (19)	0.4867 (18)
Cu1	0	0.51022 (12)	0	0.00911 (19)	0.5133 (18)
Cu2	−0.25	0.67393 (14)	0.5	0.0116 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0086 (3)	0.0089 (3)	0.0098 (3)	0	0	0
Cu1	0.0086 (3)	0.0089 (3)	0.0098 (3)	0	0	0
Cu2	0.0137 (5)	0.0105 (5)	0.0107 (5)	0	0	0

(673K-modulated)

Crystal data

Cu3.031Sn0.969	F(000) = 273
Mr = 307.6	Dx = 8.896 Mg m^−3
Orthorhombic, Xmcm(0β0)000†	Mo Kα radiation, λ = 0.7107 Å
q = 0.121550b*	Cell parameters from 2185 reflections
a = 5.529 (2) Å	θ = 4.3–28.2°
b = 4.787 (3) Å	µ = 37.66 mm^−1
c = 4.3381 (17) Å	T = 293 K
V = 114.82 (9) Å^3	Block, metallic intense silver
Z = 2	0.14 × 0.05 × 0.02 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, x₂, x₃, x₄; (3) x₁, x₂, −x₃, x₄; (4) −x₁, −x₂+2/3, −x₃+1/2, −x₄; (5) −x₁, x₂, −x₃, x₄; (6) x₁, −x₂+2/3, −x₃+1/2, −x₄; (7) −x₁, −x₂+2/3, x₃+1/2, −x₄; (8) x₁, −x₂+2/3, x₃+1/2, −x₄; (9) x₁+1/2, x₂, x₃, x₄+1/2; (10) −x₁+1/2, x₂, x₃, x₄+1/2; (11) x₁+1/2, x₂, −x₃, x₄+1/2; (12) −x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (13) −x₁+1/2, x₂, −x₃, x₄+1/2; (14) x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (15) −x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2; (16) x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2.

Data collection

Xcalibur, Eos diffractometer	598 independent reflections
Radiation source: Enhance (Mo) X-ray Source	384 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.034
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.3°, θmin = 3.2°
ω and π scans	h = −7→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −6→6
Tmin = 0.091, Tmax = 0.495	l = −5→5
6406 measured reflections

Refinement

Refinement on F^2	12 constraints
R[F^2 > 2σ(F^2)] = 0.040	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.135	(Δ/σ)max = 0.049
S = 2.90	Δρmax = 4.38 e Å^−3
598 reflections	Δρmin = −5.80 e Å^−3
24 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 330 (20)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cu2	0.25	0.17367 (16)	0.5	0.0122 (4)
Sn1	0	0.01046 (13)	0	0.0094 (3)	0.4843 (17)
Cu1	0	0.01046 (13)	0	0.0094 (3)	0.5157 (17)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu2	0.0142 (7)	0.0119 (6)	0.0104 (7)	0	0	0
Sn1	0.0089 (5)	0.0098 (5)	0.0095 (5)	0	0	0
Cu1	0.0089 (5)	0.0098 (5)	0.0095 (5)	0	0	0

(723K-modulated)

Crystal data

Cu3.022Sn0.978	F(000) = 273
Mr = 308.1	Dx = 8.931 Mg m^−3
Orthorhombic, Xmcm(0β0)000†	Mo Kα radiation, λ = 0.71073 Å
q = 0.124340b*	Cell parameters from 1695 reflections
a = 5.523 (3) Å	θ = 4.3–28.2°
b = 4.783 (3) Å	µ = 37.77 mm^−1
c = 4.336 (2) Å	T = 293 K
V = 114.54 (11) Å^3	Trigonal primatic, metallic grey
Z = 2	0.12 × 0.06 × 0.04 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, x₂, x₃, x₄; (3) x₁, x₂, −x₃, x₄; (4) −x₁, −x₂+2/3, −x₃+1/2, −x₄; (5) −x₁, x₂, −x₃, x₄; (6) x₁, −x₂+2/3, −x₃+1/2, −x₄; (7) −x₁, −x₂+2/3, x₃+1/2, −x₄; (8) x₁, −x₂+2/3, x₃+1/2, −x₄; (9) x₁+1/2, x₂, x₃, x₄+1/2; (10) −x₁+1/2, x₂, x₃, x₄+1/2; (11) x₁+1/2, x₂, −x₃, x₄+1/2; (12) −x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (13) −x₁+1/2, x₂, −x₃, x₄+1/2; (14) x₁+1/2, −x₂+2/3, −x₃+1/2, −x₄+1/2; (15) −x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2; (16) x₁+1/2, −x₂+2/3, x₃+1/2, −x₄+1/2.

Data collection

Xcalibur, Eos diffractometer	583 independent reflections
Radiation source: X-ray tube	357 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.3°, θmin = 3.2°
ω and π scans	h = −7→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −6→6
Tmin = 0.107, Tmax = 0.368	l = −5→5
4697 measured reflections

Refinement

Refinement on F^2	12 constraints
R[F^2 > 2σ(F^2)] = 0.056	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.129	(Δ/σ)max = 0.044
S = 2.34	Δρmax = 6.12 e Å^−3
583 reflections	Δρmin = −6.61 e Å^−3
24 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 830 (30)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Sn1	0	0.51013 (15)	0	0.0125 (3)	0.489 (3)
Cu1	0	0.51013 (15)	0	0.0125 (3)	0.511 (3)
Cu2	0.25	0.99298 (18)	0	0.0145 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.0108 (5)	0.0140 (5)	0.0128 (5)	0	0	0
Cu1	0.0108 (5)	0.0140 (5)	0.0128 (5)	0	0	0
Cu2	0.0148 (7)	0.0155 (7)	0.0130 (7)	0	0	0

(823K-modulated)

Crystal data

Cu3.013Sn0.987	F(000) = 273
Mr = 308.6	Dx = 8.916 Mg m^−3
Orthorhombic, Xmcm(0β0)000†	Mo Kα radiation, λ = 0.71073 Å
q = 0.100150b*	Cell parameters from 1973 reflections
a = 5.529 (2) Å	θ = 4.3–28.2°
b = 4.788 (2) Å	µ = 37.66 mm^−1
c = 4.3411 (19) Å	T = 293 K
V = 114.92 (8) Å^3	Trigonal prismatic, metallic grey
Z = 2	0.08 × 0.06 × 0.04 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, x₂, x₃, x₄; (3) x₁, x₂, −x₃+1/2, x₄; (4) −x₁, −x₂, −x₃, −x₄; (5) −x₁, x₂, −x₃+1/2, x₄; (6) x₁, −x₂, −x₃, −x₄; (7) −x₁, −x₂, x₃+1/2, −x₄; (8) x₁, −x₂, x₃+1/2, −x₄; (9) x₁+1/2, x₂, x₃, x₄+1/2; (10) −x₁+1/2, x₂, x₃, x₄+1/2; (11) x₁+1/2, x₂, −x₃+1/2, x₄+1/2; (12) −x₁+1/2, −x₂, −x₃, −x₄+1/2; (13) −x₁+1/2, x₂, −x₃+1/2, x₄+1/2; (14) x₁+1/2, −x₂, −x₃, −x₄+1/2; (15) −x₁+1/2, −x₂, x₃+1/2, −x₄+1/2; (16) x₁+1/2, −x₂, x₃+1/2, −x₄+1/2.

Data collection

Xcalibur, Eos diffractometer	932 independent reflections
Radiation source: X-ray tube	463 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.021
Detector resolution: 16.1367 pixels mm^-1	θmax = 28.3°, θmin = 3.4°
ω and π scans	h = −6→7
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.37.33 (release 27-03-2014 CrysAlis171 .NET) (compiled Mar 27 2014,17:12:48) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −6→6
Tmin = 0.152, Tmax = 0.283	l = −5→5
9463 measured reflections

Refinement

Refinement on F^2	16 constraints
R[F^2 > 2σ(F^2)] = 0.048	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
wR(F^2) = 0.133	(Δ/σ)max = 0.045
S = 2.08	Δρmax = 4.46 e Å^−3
932 reflections	Δρmin = −5.61 e Å^−3
32 parameters	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
0 restraints	Extinction coefficient: 372 (16)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cu2	0.25	0.84016 (15)	0.25	0.0130 (3)
Cu1	0	0.67710 (12)	0.75	0.0112 (2)	0.5065 (19)
Sn1	0	0.67710 (12)	0.75	0.0112 (2)	0.4935 (19)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu2	0.0145 (6)	0.0139 (5)	0.0106 (5)	0	0	0
Cu1	0.0105 (4)	0.0128 (4)	0.0103 (4)	0	0	0
Sn1	0.0105 (4)	0.0128 (4)	0.0103 (4)	0	0	0