Materials Data on K2MnSnSe4 by Materials Project
K2MnSnSe4 crystallizes in the tetragonal P-4n2 space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.44–3.64 Å. In the second K1+ site, K1+ is bonded in a distorted square co-planar geometry to four equivalent Se2- atoms. All K–Se bond lengths are 3.34 Å. In the third K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are four shorter (3.40 Å) and four longer (3.43 Å) K–Se bond lengths. There are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to four equivalent Se2- atoms to form distorted MnSe4 trigonal pyramids that share corners with four equivalent SnSe4 tetrahedra. All Mn–Se bond lengths are 2.55 Å. In the second Mn2+ site, Mn2+ is bonded to four equivalent Se2- atoms to form MnSe4 tetrahedra that share edges with two equivalent SnSe4 tetrahedra. All Mn–Se bond lengths are 2.60 Å. Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with two equivalent MnSe4 trigonal pyramids and an edgeedge with one MnSe4 tetrahedra. There are two shorter (2.58 Å) and two longer (2.59 Å) Sn–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to three K1+, one Mn2+, and one Sn4+ atom. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to four K1+, one Mn2+, and one Sn4+ atom.