p2/m or [2_02_02_02_0]
p21/m or [2_12_12_12_1]
b2/m or [2_02_02_12_1]
p2/b or (2n2n2_02_0)
p21/b or (2n2n2_12_1)
b2/b or (2n2n2_02_1)