2、1Pcc2Pma2Pca21Pnc2Pmn21Pba2Pna21Pnn2Cmm2Cmc21Ccc2Amm2Abm2Ama2Aba2Fmm2Fdd2Imm2Iba2Ima2 mmmPmmmPnnnPccmPbanPmmaPnnaPmnaPccaPbamPccnPbcmPnnmPmmnPbcnPbcaPnmaCmcmCmcaCmmmCccmCmmaCccaFmmmFdddImmmIbamIbcaImma 四方晶系4P4P41P42P43I4I41 PI 4/mP4/mP42/mP4/nP42/nI4/mI41/a