AM_Calciotantite_1 Formula: (Ca.94 Na.06) Ta3.86 Nb.13 O10.97 Name: Calciotantite Unit cell: 6.245 6.245 12.323 90.0 90.0 120.0 , V=416.21 Space group: P6322 (182)

Yamnova N A , Pushcharovsky D Yu , Voloshin A V , Soviet Physics Crystallography , 33 (1988) p.498-499, Identity of ungursaite with calciotantite and synthetic CaTa4O11, Locality: Kola Peninsula, Russia, Note: displacement parameters taken from ICSD