Gallium-tin mixing in BaGa_4-xSn_x [x = 0.89 (2)] with the BaAl₄ structure type

Single crystals of the barium trigallium tin, BaGa_3.11 (2)Sn_0.89 (2), have been obtained by a reaction of the elements in a sealed Nb tube. The title compound crystallizes with the BaAl₄-type (Pearson's code tI10), and some of the Ga atoms are replaced by Sn atoms. All atoms occupy special positions: Ba (4/mmm), Ga1/Sn1 (m2) and Ga2/Sn2 (4mm). The refined composition has also been confirmed by means of elemental microanalysis.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma]() = 0.000 Å
• Disorder in main residue
• R factor = 0.018
• wR factor = 0.039
• Data-to-parameter ratio = 10.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT077_ALERT_4_C Unitcell contains non-integer number of atoms ..          ?
PLAT301_ALERT_3_C Main Residue  Disorder .........................      25.00 Perc.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: XP in SHELXTL; software used to prepare material for publication: SHELXTL.

barium trigallium tin

Crystal data

BaGa3.11Sn0.89	Dx = 6.425 Mg m^−3
Mr = 459.80	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I4/mmm	Cell parameters from 620 reflections
Hall symbol: -I 4 2	θ = 3.9–27.3°
a = 4.7455 (14) Å	µ = 29.97 mm^−1
c = 10.554 (6) Å	T = 120 K
V = 237.68 (17) Å^3	Plate, metallic grey
Z = 2	0.07 × 0.07 × 0.06 mm
F(000) = 394

Data collection

Bruker SMART APEX CCD area-detector diffractometer	103 independent reflections
Radiation source: fine-focus sealed tube	92 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
Detector resolution: 8.3 pixels mm^-1	θmax = 27.3°, θmin = 3.9°
ω scans	h = −6→5
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −5→6
Tmin = 0.142, Tmax = 0.165	l = −13→11
651 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.018	Secondary atom site location: difference Fourier map
wR(F^2) = 0.039	w = 1/[σ^2(Fo^2) + (0.0205P)^2 + 0.0192P] where P = (Fo^2 + 2Fc^2)/3
S = 1.21	(Δ/σ)max < 0.001
103 reflections	Δρmax = 0.86 e Å^−3
10 parameters	Δρmin = −1.67 e Å^−3

Special details

Experimental. Data collection was performed with four batch runs at φ = 0.00° (450 frames), at φ = 90.00° (450 frames), at φ = 180.00° (450 frames), and at φ = 270.00° (450 frames). Frame width = 0.40° in ω. Data were merged and treated with multi-scan absorption corrections.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ba	0.0000	0.0000	0.0000	0.0114 (3)
Ga1	0.0000	0.5000	0.2500	0.0147 (3)	0.824 (8)
Sn1	0.0000	0.5000	0.2500	0.0147 (3)	0.176 (8)
Ga2	0.0000	0.0000	0.37537 (10)	0.0128 (3)	0.731 (9)
Sn2	0.0000	0.0000	0.37537 (10)	0.0128 (3)	0.269 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ba	0.0112 (3)	0.0112 (3)	0.0119 (5)	0.000	0.000	0.000
Ga1	0.0172 (4)	0.0172 (4)	0.0095 (6)	0.000	0.000	0.000
Sn1	0.0172 (4)	0.0172 (4)	0.0095 (6)	0.000	0.000	0.000
Ga2	0.0147 (4)	0.0147 (4)	0.0090 (5)	0.000	0.000	0.000
Sn2	0.0147 (4)	0.0147 (4)	0.0090 (5)	0.000	0.000	0.000

Geometric parameters (Å, º)

Ba—Sn1^i	3.5485 (13)	Ga1—Ga2^i	2.7167 (9)
Ba—Ga1^i	3.5485 (13)	Ga1—Ga2	2.7167 (9)
Ba—Ga1	3.5485 (13)	Ga1—Ba^ix	3.5485 (13)
Ba—Sn1^ii	3.5485 (13)	Ga1—Ba^x	3.5485 (13)
Ba—Ga1^ii	3.5485 (13)	Ga1—Ba^viii	3.5485 (13)
Ba—Sn1^iii	3.5485 (13)	Ga2—Sn2^xi	2.631 (3)
Ba—Ga1^iii	3.5485 (13)	Ga2—Ga2^xi	2.631 (3)
Ba—Sn1^iv	3.5485 (13)	Ga2—Sn1^iv	2.7168 (9)
Ba—Ga1^v	3.5485 (13)	Ga2—Sn1^v	2.7168 (9)
Ba—Ga1^vi	3.5485 (13)	Ga2—Ga1^iv	2.7168 (9)
Ba—Sn1^vii	3.5485 (13)	Ga2—Ga1^v	2.7168 (9)
Ga1—Sn2^iv	2.7167 (9)	Ga2—Sn1^i	2.7167 (9)
Ga1—Ga2^iv	2.7167 (9)	Ga2—Ga1^i	2.7167 (9)
Ga1—Sn2^viii	2.7167 (9)	Ga2—Ba^ix	3.6042 (10)
Ga1—Ga2^viii	2.7167 (9)	Ga2—Ba^xii	3.6042 (10)
Ga1—Sn2^i	2.7167 (9)
Sn1^i—Ba—Ga1	56.43 (2)	Sn2^iv—Ga1—Ba^ix	161.11 (2)
Sn1^i—Ba—Sn1^ii	123.57 (2)	Sn2^viii—Ga1—Ba^ix	68.77 (2)
Ga1—Ba—Sn1^ii	180.0	Ga2^iv—Ga1—Ba^ix	161.11 (2)
Sn1^i—Ba—Sn1^iii	180.0	Ga2^viii—Ga1—Ba^ix	68.77 (2)
Ga1—Ba—Sn1^iii	123.57 (2)	Sn2^i—Ga1—Ba^ix	77.18 (4)
Sn1^ii—Ba—Sn1^iii	56.43 (2)	Ga2^i—Ga1—Ba^ix	77.18 (4)
Sn1^i—Ba—Ga1^i	0.0	Ga2—Ga1—Ba^ix	68.77 (2)
Ga1—Ba—Ga1^i	56.43 (2)	Ba—Ga1—Ba^ix	123.57 (2)
Sn1^ii—Ba—Ga1^i	123.57 (2)	Sn2^iv—Ga1—Ba^x	77.18 (4)
Sn1^iii—Ba—Ga1^i	180.0	Sn2^viii—Ga1—Ba^x	68.77 (2)
Sn1^i—Ba—Ga1^ii	123.57 (2)	Ga2^iv—Ga1—Ba^x	77.18 (4)
Ga1—Ba—Ga1^ii	180.0	Ga2^viii—Ga1—Ba^x	68.77 (2)
Sn1^ii—Ba—Ga1^ii	0.0	Sn2^i—Ga1—Ba^x	161.11 (2)
Sn1^iii—Ba—Ga1^ii	56.43 (2)	Ga2^i—Ga1—Ba^x	161.11 (2)
Ga1^i—Ba—Ga1^ii	123.57 (2)	Ga2—Ga1—Ba^x	68.77 (2)
Sn1^i—Ba—Ga1^iii	180.0	Ba—Ga1—Ba^x	123.57 (2)
Ga1—Ba—Ga1^iii	123.57 (2)	Ba^ix—Ga1—Ba^x	83.93 (4)
Sn1^ii—Ba—Ga1^iii	56.43 (2)	Sn2^iv—Ga1—Ba^viii	68.77 (2)
Sn1^iii—Ba—Ga1^iii	0.0	Sn2^viii—Ga1—Ba^viii	77.18 (4)
Ga1^i—Ba—Ga1^iii	180.0	Ga2^iv—Ga1—Ba^viii	68.77 (2)
Ga1^ii—Ba—Ga1^iii	56.43 (2)	Ga2^viii—Ga1—Ba^viii	77.18 (4)
Sn1^i—Ba—Sn1^iv	83.93 (4)	Sn2^i—Ga1—Ba^viii	68.77 (2)
Ga1—Ba—Sn1^iv	56.43 (2)	Ga2^i—Ga1—Ba^viii	68.77 (2)
Sn1^ii—Ba—Sn1^iv	123.57 (2)	Ga2—Ga1—Ba^viii	161.11 (2)
Sn1^iii—Ba—Sn1^iv	96.07 (4)	Ba—Ga1—Ba^viii	83.93 (4)
Ga1^i—Ba—Sn1^iv	83.93 (4)	Ba^ix—Ga1—Ba^viii	123.57 (2)
Ga1^ii—Ba—Sn1^iv	123.57 (2)	Ba^x—Ga1—Ba^viii	123.57 (2)
Ga1^iii—Ba—Sn1^iv	96.07 (4)	Sn2^xi—Ga2—Ga2^xi	0.0
Sn1^i—Ba—Ga1^v	56.43 (2)	Sn2^xi—Ga2—Sn1^iv	119.15 (3)
Ga1—Ba—Ga1^v	83.93 (4)	Ga2^xi—Ga2—Sn1^iv	119.15 (3)
Sn1^ii—Ba—Ga1^v	96.07 (4)	Sn2^xi—Ga2—Sn1^v	119.15 (3)
Sn1^iii—Ba—Ga1^v	123.57 (2)	Ga2^xi—Ga2—Sn1^v	119.15 (3)
Ga1^i—Ba—Ga1^v	56.43 (2)	Sn1^iv—Ga2—Sn1^v	76.28 (2)
Ga1^ii—Ba—Ga1^v	96.07 (4)	Sn2^xi—Ga2—Ga1^iv	119.15 (3)
Ga1^iii—Ba—Ga1^v	123.57 (2)	Ga2^xi—Ga2—Ga1^iv	119.15 (3)
Sn1^iv—Ba—Ga1^v	56.43 (2)	Sn1^iv—Ga2—Ga1^iv	0.0
Sn1^i—Ba—Ga1^vi	96.07 (4)	Sn1^v—Ga2—Ga1^iv	76.28 (2)
Ga1—Ba—Ga1^vi	123.57 (2)	Sn2^xi—Ga2—Ga1^v	119.15 (3)
Sn1^ii—Ba—Ga1^vi	56.43 (2)	Ga2^xi—Ga2—Ga1^v	119.15 (3)
Sn1^iii—Ba—Ga1^vi	83.93 (4)	Sn1^iv—Ga2—Ga1^v	76.28 (2)
Ga1^i—Ba—Ga1^vi	96.07 (4)	Sn1^v—Ga2—Ga1^v	0.0
Ga1^ii—Ba—Ga1^vi	56.43 (2)	Ga1^iv—Ga2—Ga1^v	76.28 (2)
Ga1^iii—Ba—Ga1^vi	83.93 (4)	Sn2^xi—Ga2—Ga1	119.15 (3)
Sn1^iv—Ba—Ga1^vi	180.0	Ga2^xi—Ga2—Ga1	119.15 (3)
Ga1^v—Ba—Ga1^vi	123.57 (2)	Sn1^iv—Ga2—Ga1	76.28 (2)
Sn1^i—Ba—Sn1^vii	123.57 (2)	Sn1^v—Ga2—Ga1	121.71 (5)
Ga1—Ba—Sn1^vii	96.07 (4)	Ga1^iv—Ga2—Ga1	76.28 (2)
Sn1^ii—Ba—Sn1^vii	83.93 (4)	Ga1^v—Ga2—Ga1	121.71 (5)
Sn1^iii—Ba—Sn1^vii	56.43 (2)	Sn2^xi—Ga2—Sn1^i	119.15 (3)
Ga1^i—Ba—Sn1^vii	123.57 (2)	Ga2^xi—Ga2—Sn1^i	119.15 (3)
Ga1^ii—Ba—Sn1^vii	83.93 (4)	Sn1^iv—Ga2—Sn1^i	121.71 (5)
Ga1^iii—Ba—Sn1^vii	56.43 (2)	Sn1^v—Ga2—Sn1^i	76.28 (2)
Sn1^iv—Ba—Sn1^vii	123.57 (2)	Ga1^iv—Ga2—Sn1^i	121.71 (5)
Ga1^v—Ba—Sn1^vii	180.0	Ga1^v—Ga2—Sn1^i	76.28 (2)
Ga1^vi—Ba—Sn1^vii	56.43 (2)	Ga1—Ga2—Sn1^i	76.28 (2)
Sn2^iv—Ga1—Sn2^viii	103.72 (2)	Sn2^xi—Ga2—Ga1^i	119.15 (3)
Sn2^iv—Ga1—Ga2^iv	0.0	Ga2^xi—Ga2—Ga1^i	119.15 (3)
Sn2^viii—Ga1—Ga2^iv	103.72 (2)	Sn1^iv—Ga2—Ga1^i	121.71 (5)
Sn2^iv—Ga1—Ga2^viii	103.72 (2)	Sn1^v—Ga2—Ga1^i	76.28 (2)
Sn2^viii—Ga1—Ga2^viii	0.00 (4)	Ga1^iv—Ga2—Ga1^i	121.71 (5)
Ga2^iv—Ga1—Ga2^viii	103.72 (2)	Ga1^v—Ga2—Ga1^i	76.28 (2)
Sn2^iv—Ga1—Sn2^i	121.71 (5)	Ga1—Ga2—Ga1^i	76.28 (2)
Sn2^viii—Ga1—Sn2^i	103.72 (2)	Sn1^i—Ga2—Ga1^i	0.0
Ga2^iv—Ga1—Sn2^i	121.71 (5)	Sn2^xi—Ga2—Ba^ix	68.59 (2)
Ga2^viii—Ga1—Sn2^i	103.72 (2)	Ga2^xi—Ga2—Ba^ix	68.59 (2)
Sn2^iv—Ga1—Ga2^i	121.71 (5)	Sn1^iv—Ga2—Ba^ix	138.827 (7)
Sn2^viii—Ga1—Ga2^i	103.72 (2)	Sn1^v—Ga2—Ba^ix	138.827 (7)
Ga2^iv—Ga1—Ga2^i	121.71 (5)	Ga1^iv—Ga2—Ba^ix	138.827 (7)
Ga2^viii—Ga1—Ga2^i	103.72 (2)	Ga1^v—Ga2—Ba^ix	138.827 (7)
Sn2^i—Ga1—Ga2^i	0.00 (4)	Ga1—Ga2—Ba^ix	66.60 (2)
Sn2^iv—Ga1—Ga2	103.72 (2)	Sn1^i—Ga2—Ba^ix	66.60 (2)
Sn2^viii—Ga1—Ga2	121.71 (5)	Ga1^i—Ga2—Ba^ix	66.60 (2)
Ga2^iv—Ga1—Ga2	103.72 (2)	Sn2^xi—Ga2—Ba^xii	68.59 (2)
Ga2^viii—Ga1—Ga2	121.71 (5)	Ga2^xi—Ga2—Ba^xii	68.59 (2)
Sn2^i—Ga1—Ga2	103.72 (2)	Sn1^iv—Ga2—Ba^xii	66.60 (2)
Ga2^i—Ga1—Ga2	103.72 (2)	Sn1^v—Ga2—Ba^xii	66.60 (2)
Sn2^iv—Ga1—Ba	68.77 (2)	Ga1^iv—Ga2—Ba^xii	66.60 (2)
Sn2^viii—Ga1—Ba	161.11 (2)	Ga1^v—Ga2—Ba^xii	66.60 (2)
Ga2^iv—Ga1—Ba	68.77 (2)	Ga1—Ga2—Ba^xii	138.827 (7)
Ga2^viii—Ga1—Ba	161.11 (2)	Sn1^i—Ga2—Ba^xii	138.827 (7)
Sn2^i—Ga1—Ba	68.77 (2)	Ga1^i—Ga2—Ba^xii	138.827 (7)
Ga2^i—Ga1—Ba	68.77 (2)	Ba^ix—Ga2—Ba^xii	137.19 (4)
Ga2—Ga1—Ba	77.18 (4)

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