Materials Data on Sm(NiAs)2 by Materials Project

Abstract

Sm(NiAs)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sm2+ is bonded in a 8-coordinate geometry to eight As3- atoms. There are four shorter (3.16 Å) and four longer (3.17 Å) Sm–As bond lengths. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing NiAs4 tetrahedra. All Ni–As bond lengths are 2.42 Å. In the second Ni2+ site, Ni2+ is bonded in a 5-coordinate geometry to five As3- atoms. There are one shorter (2.35 Å) and four longer (2.39 Å) Ni–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 4-coordinate geometry to four equivalent Sm2+ and four equivalent Ni2+ atoms. In the second As3- site, As3- is bonded in a 9-coordinate geometry to four equivalent Sm2+ and five Ni2+ atoms.