Materials Data on K2Zn(SnSe3)2 by Materials Project

Abstract

K2Sn2ZnSe6 crystallizes in the tetragonal P4/ncc space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are four shorter (3.47 Å) and four longer (3.56 Å) K–Se bond lengths. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight equivalent Se2- atoms. There are four shorter (3.44 Å) and four longer (3.69 Å) K–Se bond lengths. Zn2+ is bonded to four equivalent Se2- atoms to form ZnSe4 tetrahedra that share edges with two equivalent SnSe4 tetrahedra. All Zn–Se bond lengths are 2.55 Å. Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share an edgeedge with one ZnSe4 tetrahedra and an edgeedge with one SnSe4 tetrahedra. There are two shorter (2.54 Å) and two longer (2.61 Å) Sn–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent K1+ and two equivalent Sn4+ atoms to form a mixture of distorted corner and edge-sharing SeK2Sn2 trigonal pyramids. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three K1+, one Zn2+, and one Sn4+ atom.