-    PARADAMITE     -    Zn2AsO4OH

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:  P-1 
Lattice parameters (Å):  5.6380  5.8270  6.6920 
Angles (°):  103.25  104.37  87.72 

Symmetry (theoretical): 

Space group:  P-1 
Lattice parameters (Å):  5.5242  5.7545  6.6976 
Angles (°):  103.39  104.27  88.18 

Cell contents: 

Number of atoms:  18 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Zn:  0.3932  0.2477  0.4993 
As:  0.0229  0.7376  0.1852 
Zn:  0.8275  0.2487  0.2750 
As:  0.7496  0.9629  0.1415 
H:  0.9534  0.3870  0.1252 
Zn:  0.5672  0.3893  0.3276 
Zn:  0.9584  0.7470  0.4913 
Zn:  0.3565  0.8959  0.2988 
Zn:  0.4454  0.9100  0.1898 
Zn:  0.6068  0.7523  0.5007 
Zn:  0.9771  0.2624  0.8148 
Zn:  0.1725  0.7513  0.7250 
Zn:  0.2504  0.0371  0.8585 
Zn:  0.0466  0.6130  0.8748 
Zn:  0.4328  0.6107  0.6724 
Zn:  0.0416  0.2530  0.5087 
Zn:  0.6435  0.1041  0.7012 
Zn:  0.5546  0.0900  0.8102 
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): 

Zn: 2.4148 -0.0316 -0.2727 
-0.0953 2.3785 0.2023 
0.0904 0.0828 1.6990 
Eig. Value: 2.4951 2.3348 1.6624 
As: 2.0371 0.1474 -0.1911 
-0.0605 2.4336 -0.0639 
-0.3228 0.0947 2.5811 
Eig. Value: 1.9307 2.4378 2.6833 
Zn: 3.4611 -0.0926 0.0725 
0.2311 3.5262 0.0985 
-0.2679 -0.0111 3.3473 
Eig. Value: 3.4927 3.5717 3.2702 
As: -1.6003 0.1050 -0.0304 
0.0451 -2.1511 -0.2872 
0.0334 -0.2104 -1.3450 
Eig. Value: -1.5930 -2.2301 -1.2733 
H: -1.3944 -0.5049 0.4437 
-0.4940 -1.9978 0.2722 
0.6260 0.3298 -2.0928 
Eig. Value: -0.9978 -2.7458 -1.7414 
Zn: -2.2268 0.2873 0.5577 
0.1748 -1.7261 -0.2647 
0.4601 -0.2622 -1.2381 
Eig. Value: -2.5630 -1.6399 -0.9882 
Zn: -1.7927 0.0567 -0.3143 
0.0426 -1.3070 0.1476 
-0.3075 0.1072 -2.0177 
Eig. Value: -1.5781 -1.2848 -2.2545 
Zn: -1.8463 -0.1491 -0.0382 
-0.1393 -1.4869 0.0474 
-0.2353 -0.0371 -1.4802 
Eig. Value: -1.9332 -1.3916 -1.4886 
Zn: 0.9474 0.1818 -0.2270 
0.2956 0.3305 -0.1522 
-0.0764 -0.0936 0.5465 
Eig. Value: 1.0913 0.2323 0.5008 
Zn: 2.4148 -0.0316 -0.2727 
-0.0953 2.3785 0.2023 
0.0904 0.0828 1.6990 
Eig. Value: 2.4951 2.3348 1.6624 
Zn: 2.0371 0.1474 -0.1911 
-0.0605 2.4336 -0.0639 
-0.3228 0.0947 2.5811 
Eig. Value: 1.9307 2.4378 2.6833 
Zn: 3.4611 -0.0926 0.0725 
0.2311 3.5262 0.0985 
-0.2679 -0.0111 3.3473 
Eig. Value: 3.4927 3.5717 3.2702 
Zn: -1.6003 0.1050 -0.0304 
0.0451 -2.1511 -0.2872 
0.0334 -0.2104 -1.3450 
Eig. Value: -1.5930 -2.2301 -1.2733 
Zn: -1.3944 -0.5049 0.4437 
-0.4940 -1.9978 0.2722 
0.6260 0.3298 -2.0928 
Eig. Value: -0.9978 -2.7458 -1.7414 
Zn: -2.2268 0.2873 0.5577 
0.1748 -1.7261 -0.2647 
0.4601 -0.2622 -1.2381 
Eig. Value: -2.5630 -1.6399 -0.9882 
Zn: -1.7927 0.0567 -0.3143 
0.0426 -1.3070 0.1476 
-0.3075 0.1072 -2.0177 
Eig. Value: -1.5781 -1.2848 -2.2545 
Zn: -1.8463 -0.1491 -0.0382 
-0.1393 -1.4869 0.0474 
-0.2353 -0.0371 -1.4802 
Eig. Value: -1.9332 -1.3916 -1.4886 
Zn: 0.9474 0.1818 -0.2270 
0.2956 0.3305 -0.1522 
-0.0764 -0.0936 0.5465 
Eig. Value: 1.0913 0.2323 0.5008 
Atom type 

Dielectric tensors: 

 
Ɛ3.5653 0.0327 0.0000 
0.0327 3.5967 0.0303 
0.0000 0.0303 3.4418 
Eig. Value: 3.5470 3.6210 3.4358 
Refractive index (N): 1.8882 0.1808 0.0000 
0.1808 1.8965 0.1742 
0.0000 0.1742 1.8552 
Eig. Value: 1.8834 1.9029 1.8536 
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