Modulated structure of (Ta0.72Nb0.28)Te4
Authors:Kucharczyk, D.; Budkowski, A.; Boswell, F.W.; Prodan, A.; Marinkovic, V.
Journal:Acta Cryst. B 46 153-159 (1990)
DOI:https://doi.org/10.1107/S0108768189012061
B-IncStrDB ID: 872E9Pb1p Entry date: 2010-11-08 Last revision: 2021-12-30
Ta072Nb028Te4_REFRNCE
Chemical data
Structural Formula Sum: Nb0.28 Ta0.72 Te4 [ Help ]
Formula weight: 666.7 Da [ Help ]
Crystallographic data and experimental details
a: 6.512(3) Å [ Help ]
b: 6.512(3) Å [ Help ]
c: 6.818(5) Å [ Help ]
α: 90 ° [ Help ]
β: 90 ° [ Help ]
γ: 90 ° [ Help ]
Volume: 289.1(3) Å3 [ Help ]
Z: 2 [ Help ]
μ: 33.887 mm-1 [ Help ]
Cell measurement temperature: 293 K [ Help ]
Crystal system: tetragonal [ Help ]
Space group name (H-M): P 4/m c c [ Help ]
Space group name (Hall): -P 4;-2c [ Help ]
Symmetry operations of the space group: (Show/hide table) [ Help ]
| Operation code | Operation in algebraic form |
|---|---|
| 1 | x,y,z |
| 2 | -y,x,z |
| 3 | -x,y,1/2+z |
| 4 | -x,-y,z |
| 5 | -y,-x,1/2+z |
| 6 | y,-x,z |
| 7 | x,-y,1/2+z |
| 8 | y,x,1/2+z |
| 9 | -x,-y,-z |
| 10 | y,-x,-z |
| 11 | x,-y,1/2-z |
| 12 | x,y,-z |
| 13 | y,x,1/2-z |
| 14 | -y,x,-z |
| 15 | -x,y,1/2-z |
| 16 | -y,-x,1/2-z |
Refinement details
R(obs): 0.065 [ Help ]
Structural Information
Average Structure: (Show/hide table) [ Help ]
| Atom site label | Atom symbol | Symmetry multiplicity | Occupancy | x | y | z | Uiso/equiv | ADP type |
|---|---|---|---|---|---|---|---|---|
| Ta | Ta | 2 | 0.72(2) | 0 | 0 | 0.25 | ? | Uani |
| Nb | Nb | 2 | 0.28 | 0 | 0 | 0.25 | ? | Uani |
| Te | Te | 8 | 1 | 0.1439(1) | 0.3275(1) | 0 | ? | Uani |
ADP components: (Show/hide table) [ Help ]
| Atom site label | Atom site symbol | U11 | U22 | U33 | U12 | U13 | U23 |
|---|---|---|---|---|---|---|---|
| Ta | Ta | 0.0050(3) | 0.0050(3) | 0.074(2) | 0 | 0 | 0 |
| Nb | Nb | 0.0050(3) | 0.0050(3) | 0.074(2) | 0 | 0 | 0 |
| Te | Te | 0.0172(4) | 0.0098(3) | 0.0149(3) | 0.0039(2) | 0 | 0 |
Ta072Nb028Te4_MOD
Chemical data
Structural Formula Sum: Nb0.28 Ta0.72 Te4 [ Help ]
Formula weight: 666.7 Da [ Help ]
Crystallographic data and experimental details
a: 13.024(6) Å [ Help ]
b: 13.024(6) Å [ Help ]
c: 6.818(5) Å [ Help ]
α: 90 ° [ Help ]
β: 90 ° [ Help ]
γ: 90 ° [ Help ]
Volume: 1156.5(11) Å3 [ Help ]
Z: 8 [ Help ]
μ: 33.887 mm-1 [ Help ]
Cell measurement temperature: 293 K [ Help ]
Crystal system: tetragonal [ Help ]
Superspace group name (WJJ): P:P 4/n c c:1 -1 1 1 [ Help ]
Superspace group name: P4/ncc(00γ)0000 [ Help ]
Symmetry operations of the superspace group: (Show/hide table) [ Help ]
| Operation code | Operation in algebraic form |
|---|---|
| 1 | x1,x2,x3,x4 |
| 2 | -x2,1/2+x1,x3,x4 |
| 3 | 1/2-x1,x2,1/2+x3,x4 |
| 4 | 1/2-x1,1/2-x2,x3,x4 |
| 5 | -x2,-x1,1/2+x3,x4 |
| 6 | 1/2+x2,-x1,x3,x4 |
| 7 | x1,1/2-x2,1/2+x3,x4 |
| 8 | 1/2+x2,1/2+x1,1/2+x3,x4 |
| 9 | -x1,-x2,-x3,-x4 |
| 10 | x2,1/2-x1,-x3,-x4 |
| 11 | 1/2+x1,-x2,1/2-x3,-x4 |
| 12 | 1/2+x1,1/2+x2,-x3,-x4 |
| 13 | x2,x1,1/2-x3,-x4 |
| 14 | 1/2-x2,x1,-x3,-x4 |
| 15 | -x1,1/2+x2,1/2-x3,-x4 |
| 16 | 1/2-x2,1/2-x1,1/2-x3,-x4 |
Space group name (H-M): P 4/n c c [ Help ]
Symmetry operations of the space group: (Show/hide table) [ Help ]
| Operation code | Operation in algebraic form |
|---|---|
| 1 | x,y,z |
| 2 | -y,1/2+x,z |
| 3 | 1/2-x,y,1/2+z |
| 4 | 1/2-x,1/2-y,z |
| 5 | -y,-x,1/2+z |
| 6 | 1/2+y,-x,z |
| 7 | x,1/2-y,1/2+z |
| 8 | 1/2+y,1/2+x,1/2+z |
| 9 | -x,-y,-z |
| 10 | y,1/2-x,-z |
| 11 | 1/2+x,-y,1/2-z |
| 12 | 1/2+x,1/2+y,-z |
| 13 | y,x,1/2-z |
| 14 | 1/2-y,x,-z |
| 15 | -x,1/2+y,1/2-z |
| 16 | 1/2-y,1/2-x,1/2-z |
Modulation dimension: 1 [ Help ]
Measured independent wave vectors: (Show/hide table) [ Help ]
| Wave vector id | q_x | q_y | q_z |
|---|---|---|---|
| 1 | 0 | 0 | 0.666666 |
Refinement details
Refinement remarks: Commensurate structure described within the superspace formalism. Global phase fixed at t=0. [ Help ]
Modulation functions description: Displacive modulation:Fourier series. 1st-order harmonics. [ Help ]
Structure factors calc. details: Bessel functions [ Help ]
Nb. of observed reflections: 1534 [ Help ]
R(obs): 0.058 [ Help ]
Structural Information
Average Structure: (Show/hide table) [ Help ]
| Site description | Atom site label | Atom symbol | Symmetry multiplicity | Occupancy | x | y | z | Uiso/equiv | ADP type |
|---|---|---|---|---|---|---|---|---|---|
| Ta of columns A and B | TaAB | Ta | 4 | 0.72(2) | 0.75 | 0.25 | 0.25 | ? | Uani |
| Nb of columns A and B | NbAB | Nb | 4 | 0.28 | 0.75 | 0.25 | 0.25 | ? | Uani |
| Ta of columns C and D | TaCD | Ta | 4 | 0.72(2) | 0.25 | 0.25 | 0.2469(3) | ? | Uani |
| Nb of columns C and D | NbCD | Nb | 4 | 0.28 | 0.25 | 0.25 | 0.2469(3) | ? | Uani |
| Te of columns A and B | TeAB | Te | 16 | 1 | 0.8211(2) | 0.4138(2) | 0.0000(5) | ? | Uani |
| Te of columns C and D | TeCD | Te | 16 | 1 | 0.3224(2) | 0.4133(2) | -0.0025(5) | ? | Uani |
Fourier Wave Vectors (explicit: q_x,q_y,q_z or coefficients: q_1,q_2,...): (Show/hide table) [ Help ]
| Wave vector code | q_x | q_y | q_z |
|---|---|---|---|
| 1 | 0 | 0 | 0.666666 |
Definition of the displacive (translational) Fourier series: (Show/hide table) [ Help ]
| Modulation code | Atom site label | Displacement axis | Wave vector code |
|---|---|---|---|
| TaABz1 | TaAB | z | 1 |
| NbABz1 | NbAB | z | 1 |
| TaCDz1 | TaCD | z | 1 |
| NbCDz1 | NbCD | z | 1 |
| TeABx1 | TeAB | x | 1 |
| TeABy1 | TeAB | y | 1 |
| TeABz1 | TeAB | z | 1 |
| TeCDx1 | TeCD | x | 1 |
| TeCDy1 | TeCD | y | 1 |
| TeCDz1 | TeCD | z | 1 |
Displacive (translational) Fourier coefficients: (Show/hide table) [ Help ]
| Modulation code | Cosine coefficient | Sine coefficient |
|---|---|---|
| TaABz1 | 0 | 0.0491(4) |
| NbABz1 | 0 | 0.0491(4) |
| TaCDz1 | 0.0308(4) | -0.0254(4) |
| NbCDz1 | 0.0308(4) | -0.0254(4) |
| TeABx1 | -0.0110(1) | -0.0025(2) |
| TeABy1 | -0.0058(2) | 0.0001(2) |
| TeABz1 | -0.0008(4) | 0.0086(3) |
| TeCDx1 | 0.0086(2) | 0.0023(2) |
| TeCDy1 | 0.0015(2) | 0.0061(2) |
| TeCDz1 | 0.0053(4) | -0.0054(3) |
ADP components: (Show/hide table) [ Help ]
| Atom site label | Atom site symbol | U11 | U22 | U33 | U12 | U13 | U23 |
|---|---|---|---|---|---|---|---|
| TaAB | Ta | 0.0049(1) | 0.0049(1) | 0.0102(3) | 0.0005(30) | 0 | 0 |
| NbAB | Nb | 0.0049(1) | 0.0049(1) | 0.0102(3) | 0.0005(30) | 0 | 0 |
| TaCD | Ta | 0.0049(1) | 0.0049(1) | 0.0102(3) | 0 | 0 | 0 |
| NbCD | Nb | 0.0049(1) | 0.0049(1) | 0.0102(3) | 0 | 0 | 0 |
| TeAB | Te | 0.0067(2) | 0.0062(2) | 0.0129(2) | -0.0003(1) | -0.0014(4) | -0.0018(9) |
| TeCD | Te | 0.0067(2) | 0.0062(2) | 0.0129(2) | -0.0003(1) | -0.0014(4) | -0.0018(9) |