-    THOMSENOLITE     -    NaCaAlF6.H2O

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:  14  P2_1/c 
Lattice parameters (Å):  5.5630  5.5410  16.1150 
Angles (°):  90.0  96.3  90.0 

Symmetry (theoretical): 

Space group:  14  P2_1/c 
Lattice parameters (Å):  5.5929  5.5186  16.0843 
Angles (°):  90.0  96.0  90.0 

Cell contents: 

Number of atoms:  48 
Number of atom types:  6 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.2531  0.1286  0.2478 
Ca:  0.1882  0.6693  0.0982 
Al:  0.7175  0.1723  0.1400 
F:  0.5576  0.4626  0.1235 
F:  0.9862  0.3554  0.1577 
F:  0.4404  0.0105  0.1278 
F:  0.8990  0.9079  0.1613 
F:  0.6800  0.2030  0.2497 
F:  0.7439  0.1516  0.0307 
O:  0.7987  0.6539  0.0097 
H:  0.6975  0.5895  0.0520 
H:  0.7427  0.8208  0.9978 
Na:  0.7469  0.6286  0.2522 
Ca:  0.8118  0.1693  0.4018 
Al:  0.2825  0.6723  0.3600 
F:  0.4424  0.9626  0.3765 
F:  0.0138  0.8554  0.3423 
F:  0.5596  0.5105  0.3722 
F:  0.1010  0.4079  0.3387 
F:  0.3200  0.7030  0.2503 
F:  0.2561  0.6516  0.4693 
O:  0.2013  0.1539  0.4903 
H:  0.3025  0.0895  0.4480 
H:  0.2573  0.3208  0.5022 
Na:  0.7469  0.8714  0.7522 
Ca:  0.8118  0.3307  0.9018 
Al:  0.2825  0.8277  0.8600 
F:  0.4424  0.5374  0.8765 
F:  0.0138  0.6446  0.8423 
F:  0.5596  0.9895  0.8722 
F:  0.1010  0.0921  0.8387 
F:  0.3200  0.7970  0.7503 
F:  0.2561  0.8484  0.9693 
O:  0.2013  0.3461  0.9903 
H:  0.3025  0.4105  0.9480 
H:  0.2573  0.1792  0.0022 
Na:  0.2531  0.3714  0.7478 
Ca:  0.1882  0.8307  0.5982 
Al:  0.7175  0.3277  0.6400 
F:  0.5576  0.0374  0.6235 
F:  0.9862  0.1446  0.6577 
F:  0.4404  0.4895  0.6278 
F:  0.8990  0.5921  0.6613 
F:  0.6800  0.2970  0.7497 
F:  0.7439  0.3484  0.5307 
O:  0.7987  0.8461  0.5097 
H:  0.6975  0.9105  0.5520 
H:  0.7427  0.6792  0.4978 
Atom type  X  Y  Z 

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.
 

Parameters of the Calculation 


All the calculations have been done using the ABINIT software. This is a list of the most representative parameteres used during the Raman calculation.


Number of electronic bands: 26
k-points  
   grid: 4 4 1 
   number of shifts: 1 
   shifts: 0.5 0.5 0.5 
Kinetic energy cut-off: 40 Ha  [=1088.464 eV ]
eXchange-Correlation functional: LDA pw90 

Pseudopotentials: 
Na:  sodium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local 
Ca:  calcium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 0 local 
Al:  aluminium, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local 
F:  fluorine, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local 
O:  oxygen, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local 
H:  hydrogen, fhi98PP : Trouiller-Martins-type, LDA Ceperley/Alder Perdew/Wang (1992), l= 2 local