AM_Ca2Ta2O7
Formula: Ca3.906 Nd.154 Ta3.78 Zr.16 O14
Name: Ca2Ta2O7
Unit cell: 7.356 7.356 18.116 90.0 90.0 120.0 , V=848.94
Space group: P3121 (152)

Grey I E , Mumme W G , Ness T J , Roth R S , Smith K L , Journal of Solid State Chemistry , 174 (2003) p.285-295, Structural relations between weberite and zirconolite polytypes - refinements, of doped 3T and 4M Ca2Ta2O7 and 3T CaZrTi2O7, Sample: T = 123 K, 3T weberite-type structure