Tsukimura K , Nakazawa H , Endo T , Fukunaga O , Physics and Chemistry of Minerals , 19 (1992) p.203-212, Cation distribution in Pentlandites (Fe,Ni)9S8: dependence of pressure and, temperature and kinetics of the cation exchange reaction, Sample: Synthetic, Fe/(Fe+Ni) = .556, T = 523 K, P = 0 GPa, Note: structure was not refined in this study