-    COESITE     -    SiO2

 

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:  15  C2/c 
Lattice parameters (Å):       
Angles (°):       

Symmetry (theoretical): 

Space group:  15  C2/c 
Lattice parameters (Å):  6.7498  6.7498  6.8605 
Angles (°):  75.35  104.64  58.33 

Cell contents: 

Number of atoms:  24 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Si:  0.2440  0.9855  0.0631 
Si:  0.6642  0.6467  0.5502 
O:  0.0000  0.0000  1.0000 
O:  0.5953  0.5953  0.7500 
O:  0.3723  0.9133  0.9028 
O:  0.4286  0.7650  0.3194 
O:  0.2615  0.1636  0.4631 
Si:  0.9855  0.2440  0.4369 
Si:  0.6467  0.6642  0.9498 
O:  0.0000  0.0000  0.5000 
O:  0.9133  0.3723  0.5972 
O:  0.7650  0.4286  0.1806 
O:  0.1636  0.2615  0.0369 
Si:  0.7560  0.0145  0.9369 
Si:  0.3358  0.3533  0.4498 
O:  0.4047  0.4047  0.2500 
O:  0.6277  0.0867  0.0972 
O:  0.5714  0.2350  0.6806 
O:  0.7385  0.8364  0.5369 
Si:  0.0145  0.7560  0.5631 
Si:  0.3533  0.3358  0.0502 
O:  0.0867  0.6277  0.4028 
O:  0.2350  0.5714  0.8194 
O:  0.8364  0.7385  0.9631 
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.