AM_Manganocolumbite_6 Formula: Mn.785 Fe.14 Nb1.775 Ta.177 Ti.032 Ca.009 O6 Name: Manganocolumbite Unit cell: 14.352 5.74 5.09 90.0 90.0 90.0 , V=419.32 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=0.844 from Kragero, Norway, Sample: Annealed at T = 600 C for t = 177 h, Note: Occupancies calculated assuming complete Fe/Mn disorder