Dmisteinbergite Takeuchi Y, Donnay G Acta Crystallographica 12 (1959) 465-470 The crystal structure of hexagonal CaAl2Si2O8 _database_code_amcsd 0009229 5.10 5.10 14.72 90 90 120 P6_3/mcm atom x y z occ Ca 0 0 0 Al 1/3 2/3 .1375 .5 Si 1/3 2/3 .1375 .5 O1 1/3 2/3 .25 O2 .37 0 .1