Magnetic diffraction Systematic Absences for the group Ib'a2' (#45.237) For this space group, BNS and OG settings coincide. Its label in the OG setting is given as: Ib'a2' (#45.3.333)
Values of h, k, l:  h integer, k integer, l integer
Systematic absences for general reflections (produced by centrings):
Diffraction vector type: (h k l) -> Systematic absence: h + k + l = 2n + 1