cell choice, unique axis, origin choices http://www.iucr.org/__data/iucr/cifdic_html/2/cif_sym.dic/Ispace_group.IT_coordinate_system_code.html Monoclinic, orthorhombicの場合、対称性で一意に決まらない場合は|a| Monoclinic system b-axisをuniq…