Citation: Tarantino S C; Zema M (2005). 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. American Mineralogist, 90, pp. 1291-1300.