AM_Manganocolumbite_7 Formula: (Mn.783 Fe.141 Ti.032 Nb1.775 Ta.178 Ca.009) O6 Name: Manganocolumbite Unit cell: 14.38 5.745 5.088 90.0 90.0 90.0 , V=420.34 Space group: PBCN (60)

Tarantino S C , Zema M , American Mineralogist , 90 (2005) p.1291-1300, Mixing and ordering behavior in manganocolumbite-ferrocolumbite solid solution:, A single-crystal X-ray diffraction study, Sample: KRA n4 Qm=0.922 from Kragero, Norway, Sample: Annealed at T = 700 C for t = 20 m, Note: Occupancies calculated assuming complete Fe/Mn disorder