Materials Data on KMgSb by Materials Project

Abstract

KMgSb is Matlockite structured and crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. K1+ is bonded to five equivalent Sb3- atoms to form distorted KSb5 trigonal bipyramids that share corners with twelve equivalent MgSb4 tetrahedra, corners with four equivalent KSb5 trigonal bipyramids, edges with four equivalent MgSb4 tetrahedra, and edges with eight equivalent KSb5 trigonal bipyramids. There are four shorter (3.65 Å) and one longer (3.75 Å) K–Sb bond lengths. Mg2+ is bonded to four equivalent Sb3- atoms to form MgSb4 tetrahedra that share corners with four equivalent MgSb4 tetrahedra, corners with twelve equivalent KSb5 trigonal bipyramids, edges with four equivalent MgSb4 tetrahedra, and edges with four equivalent KSb5 trigonal bipyramids. All Mg–Sb bond lengths are 2.95 Å. Sb3- is bonded in a 9-coordinate geometry to five equivalent K1+ and four equivalent Mg2+ atoms.