Where:
- filename is a string
- imol is an integer number
- a is a number
- b is a number
- c is a number
- alpha is a number
- beta is a number
- gamma is a number
- spg_info is a string
read CNS data (currently only a placeholder)
a, b,c are in Angstroems. alpha, beta, gamma are in degrees. spg is the space group info, either ;-delimited symmetry operators or the space group name