-    FANGITE     -    Tl3AsS4

The crystal structure is fully relaxed (both unit cell parameters and atomic positions under symmetry constraints) starting from an experimental structure similar to the one reported in AMCSD

Crystal Structure 


Because of the translational symmetry all the calculations are performed in the primitive unit cell and not in the conventional unit cell. The following information regarding the structure is given with respect to this primitive unit cell, which sometimes can take an unintuitive shape.

Symmetry (experimental): 

Space group:  62  Pnma 
Lattice parameters (Å):  8.8940  10.8550  9.0790 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  8.1786  9.6132  8.4402 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  32 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Tl:  0.0752  0.0462  0.1980 
Tl:  0.4047  0.2500  0.8793 
As:  0.2991  0.2500  0.4725 
S:  0.3209  0.2500  0.2109 
S:  0.0492  0.2500  0.9296 
S:  0.1554  0.0686  0.5371 
Tl:  0.4248  0.9538  0.6980 
Tl:  0.0953  0.7500  0.3793 
As:  0.2009  0.7500  0.9725 
S:  0.1791  0.7500  0.7109 
S:  0.4508  0.7500  0.4296 
S:  0.3446  0.9314  0.0371 
Tl:  0.9248  0.5462  0.8020 
Tl:  0.5953  0.7500  0.1207 
As:  0.7009  0.7500  0.5275 
S:  0.6791  0.7500  0.7891 
S:  0.9508  0.7500  0.0704 
S:  0.8446  0.5686  0.4629 
Tl:  0.5752  0.4538  0.3020 
Tl:  0.9047  0.2500  0.6207 
As:  0.7991  0.2500  0.0275 
S:  0.8209  0.2500  0.2891 
S:  0.5492  0.2500  0.5704 
S:  0.6554  0.4314  0.9629 
Tl:  0.9248  0.9538  0.8020 
S:  0.8446  0.9314  0.4629 
Tl:  0.5752  0.0462  0.3020 
S:  0.6554  0.0686  0.9629 
Tl:  0.0752  0.4538  0.1980 
S:  0.1554  0.4314  0.5371 
Tl:  0.4248  0.5462  0.6980 
S:  0.3446  0.5686  0.0371 
Atom type 

We have listed here the reduced coordinates of all the atoms in the primitive unit cell.
It is enough to know only the position of the atoms from the assymetrical unit cell and then use the symmetry to build the whole crystal structure.

Visualization of the crystal structure: 

Size:

Nx:  Ny:  Nz: 
You can define the size of the supercell to be displayed in the jmol panel as integer translations along the three crys­tallo­gra­phic axis.
Please note that the structure is represented using the pri­mi­tive cell, and not the conventional one.
   

Dielectric Properties 


We define:

  • The Born effective charges, also called dynamical charges, are tensors that correspond to the energy derivative with respect to atomic displacements and electric fields or, equivalently, to the change in atomic force due to an electric field: The sum of the Born effective charges of all nuclei in one cell must vanish, element by element, along each of the three directions of the space.
  • The dielectric tensors are the energy derivative with respect to two electric fields. They also relate the induced polarization to the external electric field.

Born effective charges (Z): 

Tl: 2.0427 -0.3999 -0.2152 
0.1129 2.3482 0.3023 
-0.3830 0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
Tl: 2.3120 0.0000 0.3438 
0.0000 2.2129 0.0000 
-0.3505 0.0000 2.3345 
Eig. Value: 2.3115 2.2129 2.3350 
As: 2.9169 -0.0000 -0.7504 
0.0000 2.9273 -0.0000 
-0.2232 0.0000 2.6295 
Eig. Value: 3.2807 2.9273 2.2656 
S: -2.3893 -0.0000 -0.2414 
-0.0000 -2.9967 -0.0000 
-0.0982 -0.0000 -1.9440 
Eig. Value: -2.4466 -2.9967 -1.8866 
S: -0.5445 0.0000 -1.1507 
0.0000 -2.5293 0.0000 
-0.7843 0.0000 -3.4375 
Eig. Value: -0.2507 -2.5293 -3.7312 
S: -3.1902 -0.4101 0.3008 
0.8075 -2.1553 -0.0553 
-0.2365 0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 -0.3999 0.2152 
0.1129 2.3482 -0.3023 
0.3830 -0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
Tl: 2.3120 0.0000 -0.3438 
0.0000 2.2129 -0.0000 
0.3505 -0.0000 2.3345 
Eig. Value: 2.3115 2.2129 2.3350 
As: 2.9169 -0.0000 0.7504 
0.0000 2.9273 0.0000 
0.2232 -0.0000 2.6295 
Eig. Value: 3.2807 2.9273 2.2656 
S: -2.3893 -0.0000 0.2414 
-0.0000 -2.9967 0.0000 
0.0982 0.0000 -1.9440 
Eig. Value: -2.4466 -2.9967 -1.8866 
S: -0.5445 0.0000 1.1507 
0.0000 -2.5293 -0.0000 
0.7843 -0.0000 -3.4375 
Eig. Value: -0.2507 -2.5293 -3.7312 
S: -3.1902 -0.4101 -0.3008 
0.8075 -2.1553 0.0553 
0.2365 -0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 0.3999 -0.2152 
-0.1129 2.3482 -0.3023 
-0.3830 -0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
Tl: 2.3120 -0.0000 0.3438 
-0.0000 2.2129 -0.0000 
-0.3505 -0.0000 2.3345 
Eig. Value: 2.3115 2.2129 2.3350 
As: 2.9169 0.0000 -0.7504 
-0.0000 2.9273 0.0000 
-0.2232 -0.0000 2.6295 
Eig. Value: 3.2807 2.9273 2.2656 
S: -2.3893 0.0000 -0.2414 
0.0000 -2.9967 0.0000 
-0.0982 0.0000 -1.9440 
Eig. Value: -2.4466 -2.9967 -1.8866 
S: -0.5445 -0.0000 -1.1507 
-0.0000 -2.5293 -0.0000 
-0.7843 -0.0000 -3.4375 
Eig. Value: -0.2507 -2.5293 -3.7312 
S: -3.1902 0.4101 0.3008 
-0.8075 -2.1553 0.0553 
-0.2365 -0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 0.3999 0.2152 
-0.1129 2.3482 0.3023 
0.3830 0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
Tl: 2.3120 -0.0000 -0.3438 
-0.0000 2.2129 0.0000 
0.3505 0.0000 2.3345 
Eig. Value: 2.3115 2.2129 2.3350 
As: 2.9169 0.0000 0.7504 
-0.0000 2.9273 -0.0000 
0.2232 0.0000 2.6295 
Eig. Value: 3.2807 2.9273 2.2656 
S: -2.3893 0.0000 0.2414 
0.0000 -2.9967 -0.0000 
0.0982 -0.0000 -1.9440 
Eig. Value: -2.4466 -2.9967 -1.8866 
S: -0.5445 -0.0000 1.1507 
-0.0000 -2.5293 0.0000 
0.7843 0.0000 -3.4375 
Eig. Value: -0.2507 -2.5293 -3.7312 
S: -3.1902 0.4101 -0.3008 
-0.8075 -2.1553 -0.0553 
0.2365 0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 -0.3999 -0.2152 
0.1129 2.3482 0.3023 
-0.3830 0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
S: -3.1902 -0.4101 0.3008 
0.8075 -2.1553 -0.0553 
-0.2365 0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 -0.3999 0.2152 
0.1129 2.3482 -0.3023 
0.3830 -0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
S: -3.1902 -0.4101 -0.3008 
0.8075 -2.1553 0.0553 
0.2365 -0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 0.3999 -0.2152 
-0.1129 2.3482 -0.3023 
-0.3830 -0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
S: -3.1902 0.4101 0.3008 
-0.8075 -2.1553 0.0553 
-0.2365 -0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Tl: 2.0427 0.3999 0.2152 
-0.1129 2.3482 0.3023 
0.3830 0.1729 2.2240 
Eig. Value: 1.8191 2.6780 2.1178 
S: -3.1902 0.4101 -0.3008 
-0.8075 -2.1553 -0.0553 
0.2365 0.0898 -2.0153 
Eig. Value: -3.2277 -2.1232 -2.0098 
Atom type 

Dielectric tensors: 

 
Ɛ22.1855 0.0000 0.0000 
0.0000 13.7973 0.0000 
0.0000 0.0000 14.3232 
Eig. Value: 22.1855 13.7973 14.3232 
Refractive index (N): 4.7101 0.0000 0.0000 
0.0000 3.7145 0.0000 
0.0000 0.0000 3.7846 
Eig. Value: 4.7101 3.7145 3.7846 
Ɛ00.0000 0.0000 0.0000 
0.0000 0.0000 0.0000 
0.0000 0.0000 0.0000 
Eig. Value: 0.0000 0.0000 0.0000