Citation: Tarantino S C; Zema M (2005). Mixing and ordering behavior in manganocolumbite-ferrocolumbite solid solution: A single-crystal X-ray diffraction study Sample: BRA n18 Qm=0.902 from S. Jose de Safira, Minas Gerais, Brazil Sample: Annealed at T = 800 C for t = 40 m Note: Occupancies calculated assuming complete Fe/Mn disorder. American Mineralogist, 90, pp. 1291-1300.