AM_Columbite-(Mn)_3 Formula: Mn.786 Fe.142 Nb1.775 Ta.178 Ti.03 Ca.008 O6 Name: Columbite-(Mn) Unit cell: 14.344 5.739 5.105 90.0 90.0 90.0 , V=420.24 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=0.674 from Kragero, Norway, Sample: Annealed at T = 500 C for t = 15 h, Note: Occupancies calculated assuming complete Fe/Mn disorder