title: Safflorite, (Co,Ni,Fe)As(2), isomorphous with marcasite.
abstract: Safflorite, a naturally occurring cobalt-nickel-iron diarsenide (Co,Ni,Fe)As(2), possesses the marcasite-type structure, with cations (M = Co + Ni + Fe) at site symmetry 2/m and As anions at m. The MAs(6) octa-hedra share two edges, forming chains parallel to c. The chemical formula for safflorite should be expressed as (Co,Ni,Fe)As(2), rather than the end-member format CoAs(2), as its structure stabilization requires the simultaneous inter-action of the electronic states of Co, Ni, and Fe with As(2) (2-) dianions.
authors.affiliation: Department of Geosciences, University of Arizona, 1040 E. 4th Street, Tucson, AZ 85721-0077, USA.
authors.forename: Hexiong
authors.initials: H
authors.lastname: Yang
authors.forename: Robert T
authors.initials: RT
authors.lastname: Downs
authors.forename: Carla
authors.initials: C
authors.lastname: Eichler