-    PYRARGYRITE     -    Ag3SbS3

Theoretical atomic positions and lattice parameters at experimental volum from 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:  161  R3c 
Lattice parameters (Å):  11.0464  11.0464  8.7211 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  161  R3c 
Lattice parameters (Å):  6.8819  6.8819  6.8819 
Angles (°):  100.49  100.49  100.49 

Cell contents: 

Number of atoms:  14 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Sb:  0.0115  0.0115  0.0115 
Ag:  0.4476  0.2313  0.9200 
S:  0.6047  0.2523  0.2706 
Ag:  0.2313  0.9200  0.4476 
S:  0.2523  0.2706  0.6047 
Sb:  0.5115  0.5115  0.5115 
Ag:  0.4200  0.7313  0.9476 
S:  0.7706  0.7523  0.1047 
Ag:  0.9200  0.4476  0.2313 
S:  0.2706  0.6047  0.2523 
Ag:  0.7313  0.9476  0.4200 
S:  0.7523  0.1047  0.7706 
Ag:  0.9476  0.4200  0.7313 
S:  0.1047  0.7706  0.7523 
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): 

Sb: 3.1869 0.2092 -0.0000 
-0.2092 3.1869 0.0000 
-0.0000 0.0000 2.3822 
Eig. Value: 3.1869 3.1869 2.3822 
Ag: 1.0127 0.1546 0.1642 
0.1576 0.6993 -0.2772 
-0.0414 -0.3351 0.7817 
Eig. Value: 1.1061 0.3911 0.9965 
S: -2.3335 -0.6419 0.6612 
-0.6325 -1.5032 0.4237 
0.3391 0.5066 -1.5758 
Eig. Value: -2.9913 -1.0464 -1.3746 
Ag: 0.6425 0.0562 -0.3222 
0.0592 1.0695 -0.0035 
-0.2695 0.2034 0.7817 
Eig. Value: 0.3911 1.1061 0.9965 
S: -1.1589 -0.0456 0.0364 
-0.0362 -2.6777 -0.7845 
0.2692 -0.5469 -1.5758 
Eig. Value: -1.0464 -2.9913 -1.3746 
Sb: 3.1869 -0.2092 0.0000 
0.2092 3.1869 -0.0000 
0.0000 -0.0000 2.3822 
Eig. Value: 3.1869 3.1869 2.3822 
Ag: 0.6425 -0.0562 0.3222 
-0.0592 1.0695 -0.0035 
0.2695 0.2034 0.7817 
Eig. Value: 0.3911 1.1061 0.9965 
S: -1.1589 0.0456 -0.0364 
0.0362 -2.6777 -0.7845 
-0.2692 -0.5469 -1.5758 
Eig. Value: -1.0464 -2.9913 -1.3746 
Ag: 0.9128 -0.2153 0.1580 
-0.2123 0.7992 0.2808 
0.3109 0.1317 0.7817 
Eig. Value: 1.1061 0.3911 0.9965 
S: -2.2626 0.6734 -0.6976 
0.6829 -1.5740 0.3608 
-0.6082 0.0404 -1.5758 
Eig. Value: -2.9913 -1.0464 -1.3746 
Ag: 1.0127 -0.1546 -0.1642 
-0.1576 0.6993 -0.2772 
0.0414 -0.3351 0.7817 
Eig. Value: 1.1061 0.3911 0.9965 
S: -2.3335 0.6419 -0.6612 
0.6325 -1.5032 0.4237 
-0.3391 0.5066 -1.5758 
Eig. Value: -2.9913 -1.0464 -1.3746 
Ag: 0.9128 0.2153 -0.1580 
0.2123 0.7992 0.2808 
-0.3109 0.1317 0.7817 
Eig. Value: 1.1061 0.3911 0.9965 
S: -2.2626 -0.6734 0.6976 
-0.6829 -1.5740 0.3608 
0.6082 0.0404 -1.5758 
Eig. Value: -2.9913 -1.0464 -1.3746 
Atom type 

Dielectric tensors: 

 
Ɛ11.0418 0.0000 0.0000 
0.0000 11.0418 0.0000 
0.0000 0.0000 9.7729 
Eig. Value: 11.0418 11.0418 9.7729 
Refractive index (N): 3.3229 0.0000 0.0000 
0.0000 3.3229 0.0000 
0.0000 0.0000 3.1262 
Eig. Value: 3.3229 3.3229 3.1262 
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