AM_Ferrocolumbite_8 Formula: Fe.791 Mn.209 Nb1.9 Ta.1 O6 Name: Ferrocolumbite Unit cell: 14.2733 5.7317 5.0646 90.0 90.0 90.0 , V=414.34 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: BRA n18 Qm=0.898 from S. Jose de Safira, Minas Gerais, Brazil, Sample: Annealed at T = 800 C for t = 7 m, Note: Occupancies calculated assuming complete Fe/Mn disorder