Used for PDB space group:
Example: 'C 1 2 1' (instead of C 2)
'P 1 2 1' (instead of P 2)
'P 1 21 1' (instead of P 21)
'P 1 1 21' (instead of P 21 -unique C axis)
'H 3' (instead of R 3 -hexagonal)
'H 3 2' (instead of R 3 2 -hexagonal)
Example: 'C 1 2 1' (instead of C 2)
'P 1 2 1' (instead of P 2)
'P 1 21 1' (instead of P 21)
'P 1 1 21' (instead of P 21 -unique C axis)
'H 3' (instead of R 3 -hexagonal)
'H 3 2' (instead of R 3 2 -hexagonal)