Arctite Formula: Na5 Ca7 Ba P6 O24 F3 Name: Arctite Unit cell: 14.366 14.366 14.366 28.58 28.58 28.58 , V=599.79 Space group: R-3M (166)
Sokolova E V , Yamnova N A , Egorov-Tismenko Yu K , Khomyakov A P , Doklady Akademii Nauk SSSR , 274 (1984) p.78-83, The crystal structure of a new phosphate of Na,Ca and Ba: (Na5Ca)Ca6Ba(PO4)6F3