AM_Columbite-(Fe)_6
Formula: (Fe.263 Nb.633 Mn.07 Ta.034) O2
Name: Columbite-(Fe)
Unit cell: 14.2501 5.7263 5.0767 90.0 90.0 90.0 , V=414.26
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=0.714 from S. Jose de Safira, Minas Gerais, Brazil, Sample: Annealed at T = 650 C for t = 20 m, Note: Occupancies calculated assuming complete Fe/Mn disorder