The (isomorphous) structures of Bi14WO24, tetradecabismuth tungsten tetracosaoxide, and Bi14MoO24, tetradecabismuth molybdenum tetracosaoxide, have been solved and refined using neutron powder diffraction data in the space group I4/m. The metal-atom array is fully ordered in terms of composition, and in terms of atomic positions deviates only slightly from a fluorite-type δ-Bi2O3-related parent structure. Three independent O-atom sites (accounting for 70 out of 78 O atoms in the unit cell) are also very close to fluorite-type parent positions. The remaining two O-atom sites, which coordinate W, exhibit partial occupancies and displacive disorder, neither of which could be better modelled by lowering of symmetry. The W site is coordinated by four O atoms in highly distorted tetrahedral coordination, the tetrahedron necessarily being orientationally disordered on that site. Nonetheless, the structure appears to be chemically reasonable.
Supporting information
| Crystallographic Information File (CIF) Contains datablocks global, W, Mo |
| Rietveld powder data file (CIF format) Contains datablock W |
| Rietveld powder data file (CIF format) Contains datablock Mo |
For both compounds, program(s) used to refine structure: GSAS.
(W) bismuth tungsten oxide
top
Crystal data top
Bi14WO24 | Neutron radiation |
Mr = 3493.57 | T = 293 K |
Tetragonal, I4/m | Particle morphology: plate |
a = 8.71083 (4) Å | yellow |
c = 17.32202 (10) Å | cylinder, 30 × 15 mm |
V = 1314.37 (1) Å3 | Specimen preparation: Prepared at 1103 K and 101.3 kPa |
Z = 2 | |
Data collection top
6Li-doped glass scintillar diffractometer | Specimen mounting: vanadium can |
Radiation source: spallation | |
Refinement top
Rp = 0.059 | Profile function: exponential pseudo-Voigt convolution Von Dreele 1990 |
Rwp = 0.061 | 56 parameters |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Bi(1) | 0.4396 (2) | 0.2132 (2) | 0.0 | 0.0175 (5)* | |
Bi(2) | 0.39520 (17) | 0.2004 (2) | 0.32999 (8) | 0.0145 (3)* | |
Bi(3) | 0.0 | 0.0 | 0.34328 (18) | 0.0313 (10)* | |
W(1) | 0.0 | 0.0 | 0.0 | 0.040 (2)* | |
O(1) | 0.0 | 0.0 | 0.1160 (5) | 0.03937 | .5 |
O(2) | 0.0 | 0.5 | 0.1213 (2) | 0.0241 (7)* | |
O(3) | 0.1937 (9) | 0.0173 (14) | 0.0 | 0.19359 | .75 |
O(4) | 0.6258 (3) | 0.3194 (2) | 0.07821 (14) | 0.0228 (5)* | |
O(5) | 0.2541 (3) | 0.0741 (2) | 0.25610 (12) | 0.0233 (5)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O(1) | 0.050 (4) | 0.050 (4) | 0.017 (5) | 0.0 | 0.0 | 0.0 |
O(3) | 0.042 (5) | 0.309 (15) | 0.230 (12) | −0.047 (6) | 0.0 | 0.0 |
(Mo) bismuth tungsten oxide
top
Crystal data top
Bi14MoO24 | Neutron radiation |
Mr = 3405.66 | T = 293 K |
Tetragonal, I4/m | Particle morphology: plate |
a = 8.70839 (4) Å | yellow |
c = 17.31634 (14) Å | cylinder, 25 × 8 mm |
V = 1313.20 (1) Å3 | Specimen preparation: Prepared at 1073 K and 101.3 kPa |
Z = 2 | |
Data collection top
3He gas and ZnS scintillation counters diffractometer | Specimen mounting: vanadium can |
Radiation source: spallation | |
Refinement top
Rp = 0.039 | Profile function: exponential pseudo-Voigt convolution Von Dreele 1990 |
Rwp = 0.025 | 56 parameters |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Bi(1) | 0.44022 (13) | 0.21306 (15) | 0.0 | 0.0097 (2)* | |
Bi(2) | 0.39542 (11) | 0.20048 (13) | 0.32975 (5) | 0.00794 (11)* | |
Bi(3) | 0.0 | 0.0 | 0.34376 (13) | 0.0159 (4)* | |
Mo(1) | 0.0 | 0.0 | 0.0 | 0.0495 (15)* | |
O(1) | 0.0 | 0.0 | 0.1189 (4) | 0.02643 | .5 |
O(2) | 0.0 | 0.5 | 0.12306 (16) | 0.0176 (4)* | |
O(3) | 0.1929 (7) | −0.0106 (16) | 0.0 | 0.19787 | .75 |
O(4) | 0.62344 (18) | 0.32173 (17) | 0.07786 (10) | 0.0157 (3)* | |
O(5) | 0.25313 (15) | 0.07313 (15) | 0.25669 (8) | 0.0108 (2)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O(1) | 0.034 (2) | 0.034 (2) | 0.012 (3) | 0.0 | 0.0 | 0.0 |
O(3) | 0.048 (5) | 0.389 (15) | 0.156 (8) | 0.024 (7) | 0.0 | 0.0 |
Structural parameters for the final Rietveld-refined structure of Bi14WO24 topSpace group I4/m (No. 87), a = 8.71083 (4), c = 17.32202 (10)Å;
Ueq=1/3ΣiΣjUijai*bj*ai.aj (A°2). |
| x(a) | y(b) | z(c) | Fraction | 100Uiso/eq* |
Bi(1) | .43964 (20) | .21318 (24) | .0 | 1.0 | 1.75 (5) |
Bi(2) | .39520 (17) | .20044 (20) | .32999 (8) | 1.0 | 1.451 (29) |
Bi(3) | .0 | .0 | .34328 (18) | 1.0 | 3.13 (10) |
W(1) | .0 | .0 | .0 | 1.0 | 3.98 (24) |
O(1) | .0 | .0 | .1160 (5) | .5 | 3.937 |
O(2) | .0 | .5 | .12133 (23) | 1.0 | 2.41 (7) |
O(3) | .1937 (9) | .0173 (14) | .0 | .75 | 19.359 |
O(4) | .62577 (26) | .31937 (24) | .07821 (14) | 1.0 | 2.28 (5) |
O(5) | .25407 (25) | .07408 (22) | .25610 (12) | 1.0 | 2.33 (5) |
* | 100U11 | 100U22 | 100U33 | 100U12 | 100U13,U23 |
O(1) | 5.0 (4) | 5.0 (4) | 1.7 (5) | 0 | 0 |
O(3) | 4.2 (5) | 30.9 (15) | 23.0 (12) | -4.7 (6) | 0 |
Structural parameters for the final Rietveld-refined structure of Bi14MoO24 topSpace group I4/m (No. 87), a = 8.70839 (4), c = 17.31634 (14)Å;
Ueq=1/3ΣiΣjUijai*bj*ai.aj (A°2). |
| x(a) | y(b) | z(c) | Fraction | 100Uiso/eq* |
Bi(1) | .44022 (13) | .21306 (15) | .0 | 1.0 | .966 (23) |
Bi(2) | .39542 (11) | .20048 (13) | .32975 (5) | 1.0 | .794 (11) |
Bi(3) | .0 | .0 | .34376 (13) | 1.0 | 1.59 (4) |
Mo(1) | .0 | .0 | .0 | 1.0 | 4.95 (15) |
O(1) | .0 | .0 | .1189 (4) | .5 | 2.643 |
O(2) | .0 | .5 | .12306 (16) | 1.0 | 1.76 (4) |
O(3) | .1929 (7) | -.0106 (16) | .0 | .75 | 19.787 |
O(4) | .62344 (18) | .32173 (17) | .07786 (10) | 1.0 | 1.571 (27) |
O(5) | .25313 (15) | .07313 (15) | .25669 (8) | 1.0 | 1.083 (21) |
* | 100U11 | 100U22 | 100U33 | 100U12 | 100U13,U23 |
O(1) | 3.35 (21) | 3.35 (21) | 1.23 (27) | 0 | 0 |
O(3) | 4.8 (5) | 38.9 (15) | 15.6 (8) | 2.4 (7) | 0 |