UP2 Pearson W B Zeitschrift fur Kristallographie 171 (1985) 23-39 The Cu2Sb and related structures _database_code_amcsd 0010896 3.810 3.81 7.764 90 90 90 P4/nmm atom x y z P1 0 0 0 P2 .5 0 .635 U .5 0 .28