The crystal of BBC is triclinic, space group: P 1. Unit cell parameters: a = 0. 646 84 (13) nm, b = 1. 324 2(3) nm, c = 1.624 5(3) nm;

• BBC晶体属三斜晶系 ；空间群为 P1 .；晶胞参数 :a =0