The structure of my material is zincblende. So normally the structure is cubic. However, when I open the primitive cell with xcrysden it dosen't look 100% cubic. It's a little bit inclined. Also when I calculated the optical properties of my material with a primitive unit cell the components of the imaginary part along x,y and z axis aren't equal (same for the real part). And normally if the structure is cubic they should be equal. Why they aren't equal?
The parameters of the conventional cell are:
nat = 8
ntyp = 2
/
CELL_PARAMETERS {alat}
1.000000000000000 0.000000000000000 0.000000000000000
0.000000000000000 1.000000000000000 0.000000000000000
0.000000000000000 0.000000000000000 1.000000000000000
For the primitive cell the parameters are:
nat = 2
ntyp = 2
/
CELL_PARAMETERS {alat}
0.500000000000000 0.500000000000000 0.000000000000000
0.500000000000000 0.000000000000000 0.500000000000000
0.000000000000000 0.500000000000000 0.500000000000000
a visualization of primitive cell using xcrysden
Can someone please clarify my doubts about this issue?