DOE OSTI2020
Er5Pt2Sb crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Er sites. In the first Er site, Er is bonded to four equivalent Pt and two equivalent Sb atoms to form distorted ErSb2Pt4 octahedra that share corners with six equivalent ErSb2Pt4 octahedra, corners with sixteen equivalent ErSb2Pt3 trigonal bipyramids, and faces with eight equivalent ErSb2Pt3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–49°. All Er–Pt bond lengths are 2.99 Å. Both Er–Sb bond lengths are 3.41 Å. In the second Er site, Er is bonded to three equivalent Pt and two equivalent Sb atoms to form distorted ErSb2Pt3 trigonal bipyramids that share corners with four equivalent ErSb2Pt4 octahedra, corners with twelve equivalent ErSb2Pt3 trigonal bipyramids, edges with seven equivalent ErSb2Pt3 trigonal bipyramids, faces with two equivalent ErSb2Pt4 octahedra, and a faceface with one ErSb2Pt3 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 42–62°. There are one shorter (2.91 Å) and two longer (2.96 Å) Er–Pt bond lengths. Both Er–Sb bond lengths are 3.26 Å. Pt is bonded in a 8-coordinate geometry to eight Er atoms. Sb is bonded in a 10-coordinate geometry to ten Er atoms.