Dear All,
I would like to calculate a structure whose symmetry group is
Bmmb. I know that is a orthorombic structure with the ab-plane adopted as a 2D
plane.
The unit cell is 1 atom of Ti and 2 of oxygen.
Cartesian axes
site n. atom positions (a_0 units)
1 Ti tau( 1) = ( 0.0000000 0.2500000 0.6800900 )
2 O tau( 2) = ( 0.0000000 0.2500000 0.3832200 )
3 O tau( 3) = ( 0.0000000 0.2500000 0.2180200 )
I tried setting ibrav = 8,
celldm(1)=a (bohr),
celldm(2)=b/a,
celldm(3)=c/a
and I got this message in the output
ortho sub-group = 2* 2 procs
warning: symmetry operation # 2 not allowed. fractional translation:
0.0000000 0.3862661 0.0000000 in crystal coordinates
warning: symmetry operation # 7 not allowed. fractional translation:
0.0000000 0.3862661 0.0000000 in crystal coordinates
Is the ibrav value not appropriate for the Bmmb space group? Can anybody
kindly help me?
Very best,
Giacomo Giorgi,
PhD. Tokyo University.
