-    VUAGNATITE     -    CaAlSiO4(OH)

 

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:  19  P2_12_12_1 
Lattice parameters (Å):  7.0550  8.5420  5.6830 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  19  P2_12_12_1 
Lattice parameters (Å):  7.0561  8.5340  5.6875 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  36 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Ca:  0.3656  0.6660  0.0296 
Al:  0.2652  0.9936  0.7391 
Si:  0.6239  0.8103  0.5125 
O:  0.4343  0.9283  0.4942 
O:  0.7932  0.9313  0.5680 
O:  0.6515  0.7101  0.2699 
O:  0.6186  0.6936  0.7410 
O:  0.3927  0.9402  0.0048 
0.5239  0.9983  0.0203 
Ca:  0.1344  0.3340  0.5296 
Al:  0.2348  0.0064  0.2391 
Si:  0.8761  0.1897  0.0125 
O:  0.0657  0.0717  0.9942 
O:  0.7068  0.0687  0.0680 
O:  0.8485  0.2899  0.7699 
O:  0.8814  0.3064  0.2410 
O:  0.1073  0.0598  0.5048 
0.9761  0.0017  0.5203 
Ca:  0.6344  0.1660  0.4704 
Al:  0.7348  0.4936  0.7609 
Si:  0.3761  0.3103  0.9875 
O:  0.5657  0.4283  0.0058 
O:  0.2068  0.4313  0.9320 
O:  0.3485  0.2101  0.2301 
O:  0.3814  0.1936  0.7590 
O:  0.6073  0.4402  0.4952 
0.4761  0.4983  0.4797 
Ca:  0.8656  0.8340  0.9704 
Al:  0.7652  0.5064  0.2609 
Si:  0.1239  0.6897  0.4875 
O:  0.9343  0.5717  0.5058 
O:  0.2932  0.5687  0.4320 
O:  0.1515  0.7899  0.7301 
O:  0.1186  0.8064  0.2590 
O:  0.8927  0.5598  0.9952 
0.0239  0.5017  0.9797 
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): 

Ca: 2.1545 -0.0022 -0.0455 
0.0247 2.3206 0.0222 
-0.0405 0.0211 2.3555 
Eig. Value: 2.1443 2.3148 2.3715 
Al: 2.8770 -0.0281 -0.1405 
0.1383 3.0275 0.3689 
0.0383 0.4120 3.0179 
Eig. Value: 2.8981 3.4131 2.6110 
Si: 3.2020 -0.1252 0.1337 
-0.1117 3.2970 0.0730 
0.0894 0.0225 2.8779 
Eig. Value: 3.1701 3.3783 2.8285 
O: -2.3727 0.5650 -0.0176 
0.4242 -1.7917 0.0044 
-0.0494 0.0423 -1.6169 
Eig. Value: -2.6573 -1.5085 -1.6155 
O: -2.3402 -0.5120 -0.1055 
-0.4791 -1.9053 0.0050 
-0.0894 0.0022 -1.4074 
Eig. Value: -2.6689 -1.5978 -1.3862 
O: -1.5459 0.1588 0.0544 
0.1974 -1.9591 -0.3884 
0.0976 -0.3880 -1.9917 
Eig. Value: -1.4638 -1.6316 -2.4014 
O: -1.5395 0.0635 0.0336 
0.1479 -2.0529 0.4221 
-0.0003 0.4080 -1.9322 
Eig. Value: -1.4698 -2.4174 -1.6373 
O: -2.1400 -0.2575 -0.0889 
-0.2619 -1.6170 -0.0111 
-0.0525 -0.0533 -1.6503 
Eig. Value: -2.2570 -1.5099 -1.6404 
1.7048 0.6513 0.1922 
0.6082 0.6810 0.0666 
0.1680 0.0615 0.3472 
Eig. Value: 2.0260 0.3874 0.3195 
Ca: 2.1545 -0.0022 0.0455 
0.0247 2.3206 -0.0222 
0.0405 -0.0211 2.3555 
Eig. Value: 2.1443 2.3148 2.3715 
Al: 2.8770 -0.0281 0.1405 
0.1383 3.0275 -0.3689 
-0.0383 -0.4120 3.0179 
Eig. Value: 2.8981 3.4131 2.6110 
Si: 3.2020 -0.1252 -0.1337 
-0.1117 3.2970 -0.0730 
-0.0894 -0.0225 2.8779 
Eig. Value: 3.1701 3.3783 2.8285 
O: -2.3727 0.5650 0.0176 
0.4242 -1.7917 -0.0044 
0.0494 -0.0423 -1.6170 
Eig. Value: -2.6573 -1.5085 -1.6155 
O: -2.3402 -0.5120 0.1055 
-0.4791 -1.9053 -0.0050 
0.0894 -0.0022 -1.4073 
Eig. Value: -2.6689 -1.5978 -1.3862 
O: -1.5459 0.1588 -0.0544 
0.1974 -1.9591 0.3884 
-0.0976 0.3880 -1.9917 
Eig. Value: -1.4638 -1.6316 -2.4014 
O: -1.5395 0.0635 -0.0336 
0.1479 -2.0529 -0.4221 
0.0003 -0.4080 -1.9321 
Eig. Value: -1.4698 -2.4174 -1.6373 
O: -2.1400 -0.2575 0.0889 
-0.2619 -1.6170 0.0111 
0.0525 0.0533 -1.6503 
Eig. Value: -2.2570 -1.5099 -1.6404 
1.7048 0.6513 -0.1922 
0.6082 0.6810 -0.0666 
-0.1680 -0.0615 0.3472 
Eig. Value: 2.0260 0.3874 0.3195 
Ca: 2.1545 0.0022 -0.0455 
-0.0247 2.3206 -0.0222 
-0.0405 -0.0211 2.3555 
Eig. Value: 2.1443 2.3148 2.3715 
Al: 2.8770 0.0281 -0.1405 
-0.1383 3.0275 -0.3689 
0.0383 -0.4120 3.0179 
Eig. Value: 2.8981 3.4131 2.6110 
Si: 3.2020 0.1252 0.1337 
0.1117 3.2970 -0.0730 
0.0894 -0.0225 2.8779 
Eig. Value: 3.1701 3.3783 2.8285 
O: -2.3727 -0.5650 -0.0176 
-0.4242 -1.7917 -0.0044 
-0.0494 -0.0423 -1.6170 
Eig. Value: -2.6573 -1.5085 -1.6155 
O: -2.3402 0.5120 -0.1055 
0.4791 -1.9053 -0.0050 
-0.0894 -0.0022 -1.4073 
Eig. Value: -2.6689 -1.5978 -1.3862 
O: -1.5459 -0.1588 0.0544 
-0.1974 -1.9591 0.3884 
0.0976 0.3880 -1.9917 
Eig. Value: -1.4638 -1.6316 -2.4014 
O: -1.5395 -0.0635 0.0336 
-0.1479 -2.0529 -0.4221 
-0.0003 -0.4080 -1.9321 
Eig. Value: -1.4698 -2.4174 -1.6373 
O: -2.1400 0.2575 -0.0889 
0.2619 -1.6170 0.0111 
-0.0525 0.0533 -1.6503 
Eig. Value: -2.2570 -1.5099 -1.6404 
1.7048 -0.6513 0.1922 
-0.6082 0.6810 -0.0666 
0.1680 -0.0615 0.3472 
Eig. Value: 2.0260 0.3874 0.3195 
Ca: 2.1545 0.0022 0.0455 
-0.0247 2.3206 0.0222 
0.0405 0.0211 2.3555 
Eig. Value: 2.1443 2.3148 2.3715 
Al: 2.8770 0.0281 0.1405 
-0.1383 3.0275 0.3689 
-0.0383 0.4120 3.0179 
Eig. Value: 2.8981 3.4131 2.6110 
Si: 3.2020 0.1252 -0.1337 
0.1117 3.2970 0.0730 
-0.0894 0.0225 2.8779 
Eig. Value: 3.1701 3.3783 2.8285 
O: -2.3727 -0.5650 0.0176 
-0.4242 -1.7917 0.0044 
0.0494 0.0423 -1.6169 
Eig. Value: -2.6573 -1.5085 -1.6155 
O: -2.3402 0.5120 0.1055 
0.4791 -1.9053 0.0050 
0.0894 0.0022 -1.4074 
Eig. Value: -2.6689 -1.5978 -1.3862 
O: -1.5459 -0.1588 -0.0544 
-0.1974 -1.9591 -0.3884 
-0.0976 -0.3880 -1.9917 
Eig. Value: -1.4638 -1.6316 -2.4014 
O: -1.5395 -0.0635 -0.0336 
-0.1479 -2.0529 0.4221 
0.0003 0.4080 -1.9322 
Eig. Value: -1.4698 -2.4174 -1.6373 
O: -2.1400 0.2575 0.0889 
0.2619 -1.6170 -0.0111 
0.0525 -0.0533 -1.6503 
Eig. Value: -2.2570 -1.5099 -1.6404 
1.7048 -0.6513 -0.1922 
-0.6082 0.6810 0.0666 
-0.1680 0.0615 0.3472 
Eig. Value: 2.0260 0.3874 0.3195 
Atom type 

Dielectric tensors: 

 
Ɛ3.0543 0.0000 0.0000 
0.0000 3.0225 0.0000 
0.0000 0.0000 2.9499 
Eig. Value: 3.0543 3.0225 2.9499 
Refractive index (N): 1.7477 0.0000 0.0000 
0.0000 1.7385 0.0000 
0.0000 0.0000 1.7175 
Eig. Value: 1.7477 1.7385 1.7175 
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