-    PHENAKITE     -    Be2SiO4

 

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:  148  R-3 
Lattice parameters (Å):  6.5817  6.5817  4.3558 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  148  R-3 
Lattice parameters (Å):  7.5742  7.5742  7.5742 
Angles (°):  108.03  108.03  108.03 

Cell contents: 

Number of atoms:  42 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Be:  0.0000  0.6098  0.4311 
Be:  0.2057  0.2786  0.1027 
Si:  0.8723  0.9455  0.7664 
O:  0.5379  0.9594  0.6284 
O:  0.6629  0.0849  0.7493 
O:  0.4157  0.0380  0.0056 
O:  0.7059  0.7049  0.6706 
Be:  0.3742  0.4311  0.2057 
Be:  0.6098  0.1027  0.8723 
Si:  0.2786  0.7664  0.5379 
O:  0.9455  0.6284  0.6629 
O:  0.9594  0.7493  0.4157 
O:  0.0849  0.0056  0.7059 
O:  0.0380  0.6706  0.3742 
Be:  0.7049  0.2057  0.6098 
Be:  0.4311  0.8723  0.2786 
Si:  0.1027  0.5379  0.9455 
O:  0.7664  0.6629  0.9594 
O:  0.6284  0.4157  0.0849 
O:  0.7493  0.7059  0.0380 
O:  0.0056  0.3742  0.7049 
Be:  0.6706  0.3902  0.5689 
Be:  0.7943  0.7214  0.8973 
Si:  0.1277  0.0545  0.2336 
O:  0.4621  0.0406  0.3716 
O:  0.3371  0.9151  0.2507 
O:  0.5843  0.9620  0.9944 
O:  0.2941  0.2951  0.3294 
Be:  0.6258  0.5689  0.7943 
Be:  0.3902  0.8973  0.1277 
Si:  0.7214  0.2336  0.4621 
O:  0.0545  0.3716  0.3371 
O:  0.0406  0.2507  0.5843 
O:  0.9151  0.9944  0.2941 
O:  0.9620  0.3294  0.6258 
Be:  0.2951  0.7943  0.3902 
Be:  0.5689  0.1277  0.7214 
Si:  0.8973  0.4621  0.0545 
O:  0.2336  0.3371  0.0406 
O:  0.3716  0.5843  0.9151 
O:  0.2507  0.2941  0.9620 
O:  0.9944  0.6258  0.2951 
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.