The Interface-Modulated Structure of TaSi0.360Te2

Authors:

van der Lee, A.; Evain, M.; Monconduit, L.; Brec, R.; Rouxel, J.; Petricek, V.

Journal:

Acta Crystallographica Section B 50 119-128 (1994)

DOI:

https://doi.org/10.1107/S0108768193011644

B-IncStrDB ID: 7Df7oKD25A6 Entry date: 2021-10-26 Last revision: 2021-12-30

mod1007986593

Chemical data


Structural Formula: Ta Si0.306 Te2 [ Help ]

Structural Formula Sum: Si0.306 Ta Te [ Help ]

Crystallographic data and experimental details


a: 6.329(3) Å [ Help ]

b: 14.031(3) Å [ Help ]

c: 3.8258(7) Å [ Help ]

α: 90 ° [ Help ]

β: 90 ° [ Help ]

γ: 90 ° [ Help ]

Volume: 339.72 Å3 [ Help ]

Z: 4 [ Help ]

Modulation dimension: 1 [ Help ]

Measured independent wave vectors: [ Help ]

Wave vector id q_x q_y q_z
1 0 0 0.3602(8)

Crystal system: orthorhombic [ Help ]

Superspace group name (ITC): Pnma(0 0 γ)s00 [ Help ]

Symmetry operations of the superspace group: [ Help ]

Operation code Operation in algebraic form
1 x1,x2,x3,x4
2 -x1+1/2,-x2,x3+1/2,x4+1/2
3 -x1,x2+1/2,-x3,-x4
4 x1+1/2,-x2+1/2,-x3+1/2,-x4+1/2
5 -x1,-x2,-x3,-x4
6 x1+1/2,x2,-x3+1/2,-x4+1/2
7 x1,-x2+1/2,x3,x4
8 -x1+1/2,x2+1/2,x3+1/2,x4+1/2

Refinement details


Nb. of observed reflections: 1907 [ Help ]

R(obs): 0.099 [ Help ]

wR(obs): 0.110 [ Help ]

Refinement remarks: Model II (crenel modulations for occupation) [ Help ]

Structural Information


Average Structure: [ Help ]

Atom site label Occupancy x y z ADP type
Ta(1) 0.617(2) 0.3208(2) 0.25 -0.0390(4) Uani
Ta(2) 0.383(2) 0.037(4) 0.25 -0.001(4) Uani
Si 0.31(3) 0.44(1) 0.25 0.32(2) Uani
Te 1 0.1670(2) 0.11676(8) 0.4771(3) Uani

Fourier Wave Vectors (explicit: q_x,q_y,q_z or coefficients: q_1,q_2,...): [ Help ]

Wave vector code q_x q_y q_z
1 0 0 0.3602
2 0 0 0.7204
3 0 0 1.0806
4 0 0 1.4408

Definition of the displacive (translational) Fourier series: [ Help ]

Modulation code Atom site label Displacement axis Wave vector code
Ta1x1 Ta(1) x 1
Ta1x2 Ta(1) x 2
Ta1x3 Ta(1) x 3
Ta1z1 Ta(1) z 1
Ta1z2 Ta(1) z 2
Ta1z3 Ta(1) z 3
Ta2x1 Ta(2) x 1
Ta2x2 Ta(2) x 2
Ta2x3 Ta(2) x 3
Ta2z1 Ta(2) z 1
Ta2z2 Ta(2) z 2
Ta2z3 Ta(2) z 3
Six1 Si x 1
Siz1 Si z 1
Tex1 Te x 1
Tex2 Te x 2
Tex3 Te x 3
Tex4 Te x 4
Tey1 Te y 1
Tey2 Te y 2
Tey3 Te y 3
Tey4 Te y 4
Tez1 Te z 1
Tez2 Te z 2
Tez3 Te z 3
Tez4 Te z 4

Displacive (translational) Fourier coefficients: [ Help ]

Modulation code Sine coefficient Cosine coefficient
Ta1x1 -0.0130(4) 0
Ta1x2 -0.0075(5) 0
Ta1x3 -0.0013(8) 0
Ta1z1 -0.0600(6) 0
Ta1z2 -0.019(1) 0
Ta1z3 0.008(1) 0
Ta2x1 0.013(8) 0.0
Ta2x2 0.012(6) 0.0
Ta2x3 0.007(3) 0.0
Ta2z1 0.122(8) 0.0
Ta2z2 0.064(6) 0.0
Ta2z3 0.033(4) 0.0
Six1 0.02(1) 0.0
Siz1 0.06(3) 0.0
Tex1 0.0187(3) 0.0261(3)
Tex2 -0.0086(3) 0.0178(3)
Tex3 0.0076(5) 0.0005(7)
Tex4 0.002(1) -0.0034(9)
Tey1 -0.0022(2) 0.0013(2)
Tey2 0.0021(2) 0.0006(2)
Tey3 -0.0002(3) 0.0001(4)
Tey4 -0.0019(7) 0.0005(8)
Tez1 -0.0189(5) 0.0073(5)
Tez2 0.0200(6) 0.0027(7)
Tez3 -0.03(1) 0.005(1)
Tez4 0.008(2) -0.013(2)

Definition of the occupation Fourier series: [ Help ]

Modulation code Atom site label Wave vector code
Ta1o1 Ta(1) 1
Ta1o2 Ta(1) 2
Ta2o1 Ta(2) 1
Ta2o2 Ta(2) 2
Sio1 Si 1
Sio2 Si 2

Occupation crenel coefficients: [ Help ]

Atom site label Center (x0) Width
Ta(1) 0.829(1) 0.634(2)
Ta(2) 0.329(2) 0.366(1)
Si 0.47(1) 0.38(2)