AM_Manganocolumbite_8 Formula: Mn.783 Fe.14 Ti.033 Ta.179 Ca.009 Nb1.774 O6 Name: Manganocolumbite Unit cell: 14.38 5.75 5.084 90.0 90.0 90.0 , V=420.37 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=0.960 from Kragero, Norway, Sample: Annealed at T = 800 C for t = 15 m, Note: Occupancies calculated assuming complete Fe/Mn disorder