Materials Data on K2Ni3Se4 by Materials Project
K2Ni3Se4 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight equivalent Se2- atoms. There are a spread of K–Se bond distances ranging from 3.53–3.56 Å. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a square co-planar geometry to four equivalent Se2- atoms. All Ni–Se bond lengths are 2.35 Å. In the second Ni2+ site, Ni2+ is bonded in a square co-planar geometry to four equivalent Se2- atoms. There are two shorter (2.34 Å) and two longer (2.35 Å) Ni–Se bond lengths. Se2- is bonded in a 7-coordinate geometry to four equivalent K1+ and three Ni2+ atoms.