Crystal structure of Na₂HfSi₂O₇ by Rietveld refinement

A new sodium hafnium disilicate was detected as an major inter­mediate product of a global reaction between borosilicate glass and hafnium. The composition of this phase was determined to be Na₂HfSi₂O₇ by laboratory powder diffraction and Rietveld refinement.

Key indicators

• Powder X-ray study
• T = 293 K
• Mean [sigma](Si-O) = 0.017 Å
• R factor = 0.024
• wR factor = 0.000
• Data-to-parameter ratio = 0.0

checkCIF/PLATON results

No syntax errors found



Alert level C
GOODF01_ALERT_2_C  The least squares goodness of fit parameter lies
            outside the range 0.80 <> 2.00
            Goodness of fit given =      2.230
PLAT155_ALERT_4_C The Triclinic Unitcell is NOT Reduced ..........     Please Do !

Alert level G
PLAT004_ALERT_5_G Polymeric Structure Found with Maximum Dimension          3 Info
PLAT396_ALERT_2_G Deviating Si-O-Si Angle from 150 Deg for      O2      136.7 Degree
PLAT793_ALERT_4_G The Model has Chirality at Si1     (Centro SPGR)          R Verify
PLAT793_ALERT_4_G The Model has Chirality at Si2     (Centro SPGR)          S Verify

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 ALERT level G = General information/check it is not something unexpected

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

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Computing details

Data collection: X'Pert Data Collector (PANalytical, 2011); cell refinement: JANA2006 (Petříček et al., 2014); data reduction: JANA2006 (Petříček et al., 2014); program(s) used to solve structure: JANA2006 (Petříček et al., 2014); program(s) used to refine structure: JANA2006 (Petříček et al., 2014); molecular graphics: VESTA (Momma & Izumi, 2011); software used to prepare material for publication: publCIF (Westrip, 2010).

Disodium hafnium disilicate

Crystal data

Na2HfSi2O7	Z = 2
Mr = 392.6	F(000) = 356
Triclinic, P1	Dx = 4.387 Mg m^−3
a = 6.6123 (2) Å	Cu Kα1 radiation, λ = 1.540562, 1.544390 Å
b = 8.7948 (3) Å	T = 293 K
c = 5.41074 (15) Å	Particle morphology: plate-like
α = 92.603 (2)°	white
β = 94.0843 (18)°	flat_sheet, 25 × 25 mm
γ = 71.3262 (18)°	Specimen preparation: Prepared at 1393 K and 100 kPa
V = 297.25 (2) Å^3

Data collection

Panalytical XPert MPD Pro diffractometer	Data collection mode: reflection
Radiation source: sealed X-ray tube	Scan method: step
Specimen mounting: packed powder pellet	2θmin = 8.013°, 2θmax = 120.013°, 2θstep = 0.017°

Refinement

Rp = 0.024	67 parameters
Rwp = 0.032	0 restraints
Rexp = 0.015	6 constraints
R(F) = 0.024	Weighting scheme based on measured s.u.'s
6423 data points	(Δ/σ)max = 0.005
Profile function: pseudo-Voigt	Background function: Legendre polynoms

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

	x	y	z	Uiso*/Ueq
Na1	0.8823 (15)	0.0970 (12)	0.2630 (18)	0.035 (4)*
Na2	0.3456 (14)	0.5024 (10)	0.7608 (18)	0.011 (3)*
Hf1	0.2880 (3)	0.2710 (2)	0.2201 (3)	0.0158 (7)
Si1	0.6528 (13)	0.1435 (9)	0.7769 (13)	0.010 (3)*
Si2	0.9381 (12)	0.3380 (8)	0.6861 (15)	0.006 (2)*
O1	0.307 (2)	0.0382 (17)	0.172 (3)	0.0030 (15)*
O2	0.865 (2)	0.1777 (14)	0.727 (2)	0.0030 (15)*
O3	0.494 (2)	0.2081 (15)	0.530 (3)	0.0030 (15)*
O4	0.562 (2)	0.2522 (15)	0.020 (3)	0.0030 (15)*
O5	−0.003 (2)	0.3116 (14)	0.401 (3)	0.0030 (15)*
O6	0.120 (2)	0.3300 (14)	0.872 (3)	0.0030 (15)*
O7	0.284 (2)	0.5148 (14)	0.288 (3)	0.0030 (15)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hf1	0.0148 (10)	0.0177 (11)	0.0126 (10)	0.0003 (7)	0.0035 (7)	0.0111 (8)

Geometric parameters (Å, º)

O1—Hf1	2.017 (15)	Na1—Na1^vii	3.169 (13)
O1—Si1^i	1.568 (17)	Na1—Na2^v	3.363 (13)
O2—Si1	1.567 (18)	Na1—Hf1^viii	3.513 (12)
O2—Si2	1.660 (17)	Na1—Si1^ii	2.919 (12)
O3—Hf1	2.060 (13)	Na1—Si1	3.210 (13)
O3—Si1	1.644 (15)	Na1—Si1^vii	3.140 (11)
O4—Na1	2.450 (15)	Na1—Si2	3.132 (13)
O4—Si1^ii	1.622 (15)	Na2—Na2^v	3.590 (14)
O5—Na1^iii	2.323 (18)	Na2—Na2^ix	3.174 (13)
O5—Si2^iii	1.605 (16)	Na2—Hf1	3.556 (9)
O6—Hf1^iv	2.115 (13)	Na2—Hf1^iv	3.399 (10)
O6—Si2^iii	1.497 (16)	Na2—Hf1^v	3.590 (10)
O7—Na2^v	2.441 (18)	Na2—Si1	3.161 (10)
O7—Si2^v	1.625 (13)	Na2—Si2^v	3.052 (11)
Na1—Na1^vi	3.453 (14)
Hf1—O1—Si1^i	161.7 (9)	Na2^ix—Na2—Si1	76.2 (3)
Si1—O2—Si2	136.8 (8)	Na2^ix—Na2—Si2^v	153.7 (4)
Hf1—O3—Si1	175.1 (10)	Hf1—Na2—Hf1^iv	102.1 (3)
Na1—O4—Si1^ii	89.2 (6)	Hf1—Na2—Hf1^v	119.7 (3)
Na1^iii—O5—Si2^iii	104.3 (9)	Hf1—Na2—Si1	66.6 (2)
Hf1^iv—O6—Si2^iii	153.3 (10)	Hf1—Na2—Si2^v	59.6 (2)
Na2^v—O7—Si2^v	134.4 (9)	Hf1^iv—Na2—Hf1^v	126.1 (3)
O4—Na1—O5^viii	97.2 (6)	Hf1^iv—Na2—Si1	62.6 (2)
O4—Na1—Na1^vi	91.7 (4)	Hf1^iv—Na2—Si2^v	134.1 (4)
O4—Na1—Na1^vii	152.6 (6)	Hf1^v—Na2—Si1	102.9 (3)
O4—Na1—Na2^v	51.1 (4)	Hf1^v—Na2—Si2^v	97.7 (3)
O4—Na1—Hf1^viii	109.2 (5)	Si1—Na2—Si2^v	125.7 (4)
O4—Na1—Si1^ii	33.8 (4)	O1—Hf1—O3	88.5 (5)
O4—Na1—Si1	95.1 (5)	O1—Hf1—O6^ii	91.8 (5)
O4—Na1—Si1^vii	143.7 (5)	O1—Hf1—Na1^iii	51.7 (4)
O4—Na1—Si2	103.7 (5)	O1—Hf1—Na2^ii	123.8 (4)
O5^viii—Na1—Na1^vi	114.1 (6)	O1—Hf1—Na2	131.8 (4)
O5^viii—Na1—Na1^vii	89.9 (5)	O1—Hf1—Na2^v	136.4 (4)
O5^viii—Na1—Na2^v	46.9 (4)	O3—Hf1—O6^ii	171.1 (6)
O5^viii—Na1—Hf1^viii	36.4 (4)	O3—Hf1—Na1^iii	107.6 (5)
O5^viii—Na1—Si1^ii	113.7 (5)	O3—Hf1—Na2^ii	124.6 (5)
O5^viii—Na1—Si1	85.7 (5)	O3—Hf1—Na2	50.0 (4)
O5^viii—Na1—Si1^vii	94.3 (5)	O3—Hf1—Na2^v	71.4 (5)
O5^viii—Na1—Si2	29.8 (4)	O6^ii—Hf1—Na1^iii	79.4 (4)
Na1^vi—Na1—Na1^vii	109.5 (3)	O6^ii—Hf1—Na2^ii	48.7 (4)
Na1^vi—Na1—Na2^v	116.9 (4)	O6^ii—Hf1—Na2	133.2 (3)
Na1^vi—Na1—Hf1^viii	79.2 (3)	O6^ii—Hf1—Na2^v	102.6 (4)
Na1^vi—Na1—Si1^ii	58.3 (3)	Na1^iii—Hf1—Na2^ii	127.8 (2)
Na1^vi—Na1—Si1	158.2 (4)	Na1^iii—Hf1—Na2	111.9 (2)
Na1^vi—Na1—Si1^vii	52.3 (2)	Na1^iii—Hf1—Na2^v	171.0 (2)
Na1^vi—Na1—Si2	141.2 (4)	Na2^ii—Hf1—Na2	102.1 (2)
Na1^vii—Na1—Na2^v	125.8 (4)	Na2^ii—Hf1—Na2^v	53.9 (2)
Na1^vii—Na1—Hf1^viii	92.0 (3)	Na2—Hf1—Na2^v	60.3 (2)
Na1^vii—Na1—Si1^ii	156.1 (5)	O1^i—Si1—O2	111.9 (8)
Na1^vii—Na1—Si1	59.0 (3)	O1^i—Si1—O3	113.6 (9)
Na1^vii—Na1—Si1^vii	61.2 (3)	O1^i—Si1—O4^iv	109.9 (9)
Na1^vii—Na1—Si2	70.6 (3)	O1^i—Si1—Na1	97.9 (6)
Na2^v—Na1—Hf1^viii	71.7 (3)	O1^i—Si1—Na1^iv	76.2 (6)
Na2^v—Na1—Si1^ii	76.5 (3)	O1^i—Si1—Na1^vii	61.5 (6)
Na2^v—Na1—Si1	83.1 (3)	O1^i—Si1—Na2	150.4 (7)
Na2^v—Na1—Si1^vii	135.6 (5)	O2—Si1—O3	104.6 (8)
Na2^v—Na1—Si2	55.9 (3)	O2—Si1—O4^iv	105.7 (9)
Hf1^viii—Na1—Si1^ii	104.5 (4)	O2—Si1—Na1	52.6 (6)
Hf1^viii—Na1—Si1	117.6 (3)	O2—Si1—Na1^iv	77.6 (6)
Hf1^viii—Na1—Si1^vii	64.0 (3)	O2—Si1—Na1^vii	50.5 (5)
Hf1^viii—Na1—Si2	62.2 (3)	O2—Si1—Na2	97.4 (6)
Si1^ii—Na1—Si1	123.9 (4)	O3—Si1—O4^iv	110.8 (7)
Si1^ii—Na1—Si1^vii	110.6 (4)	O3—Si1—Na1	64.3 (6)
Si1^ii—Na1—Si2	132.4 (4)	O3—Si1—Na1^iv	167.4 (6)
Si1—Na1—Si1^vii	120.1 (3)	O3—Si1—Na1^vii	121.8 (6)
Si1—Na1—Si2	56.5 (3)	O3—Si1—Na2	59.9 (5)
Si1^vii—Na1—Si2	103.3 (3)	O4^iv—Si1—Na1	150.5 (8)
O7^v—Na2—Na1^v	99.3 (5)	O4^iv—Si1—Na1^iv	57.1 (5)
O7^v—Na2—Na2^v	45.5 (4)	O4^iv—Si1—Na1^vii	125.7 (6)
O7^v—Na2—Na2^ix	60.6 (4)	O4^iv—Si1—Na2	55.6 (5)
O7^v—Na2—Hf1	96.4 (4)	Na1—Si1—Na1^iv	123.9 (4)
O7^v—Na2—Hf1^iv	113.5 (4)	Na1—Si1—Na1^vii	59.9 (3)
O7^v—Na2—Hf1^v	35.8 (3)	Na1—Si1—Na2	103.3 (3)
O7^v—Na2—Si1	68.4 (4)	Na1^iv—Si1—Na1^vii	69.4 (3)
O7^v—Na2—Si2^v	110.4 (5)	Na1^iv—Si1—Na2	107.6 (3)
Na1^v—Na2—Na2^v	91.8 (3)	Na1^vii—Si1—Na2	147.9 (4)
Na1^v—Na2—Na2^ix	97.3 (3)	O2—Si2—O5^viii	100.7 (8)
Na1^v—Na2—Hf1	117.5 (3)	O2—Si2—O6^viii	106.7 (8)
Na1^v—Na2—Hf1^iv	124.7 (3)	O2—Si2—O7^v	102.8 (8)
Na1^v—Na2—Hf1^v	64.7 (3)	O2—Si2—Na1	55.3 (5)
Na1^v—Na2—Si1	167.6 (4)	O2—Si2—Na2^v	103.7 (6)
Na1^v—Na2—Si2^v	58.2 (3)	O5^viii—Si2—O6^viii	116.1 (9)
Na2^v—Na2—Na2^ix	106.1 (3)	O5^viii—Si2—O7^v	109.8 (8)
Na2^v—Na2—Hf1	60.3 (2)	O5^viii—Si2—Na1	46.0 (6)
Na2^v—Na2—Hf1^iv	142.8 (3)	O5^viii—Si2—Na2^v	53.3 (5)
Na2^v—Na2—Hf1^v	59.4 (2)	O6^viii—Si2—O7^v	118.2 (8)
Na2^v—Na2—Si1	80.2 (3)	O6^viii—Si2—Na1	131.2 (6)
Na2^v—Na2—Si2^v	68.4 (3)	O6^viii—Si2—Na2^v	149.4 (8)
Na2^ix—Na2—Hf1	141.7 (3)	O7^v—Si2—Na1	110.3 (6)
Na2^ix—Na2—Hf1^iv	66.1 (3)	O7^v—Si2—Na2^v	57.1 (6)
Na2^ix—Na2—Hf1^v	60.0 (3)	Na1—Si2—Na2^v	65.9 (3)

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