Materials Data on Ho5(SiSb)2 by Materials Project

Abstract

Ho5(SiSb)2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded to three equivalent Si and three equivalent Sb atoms to form distorted HoSi3Sb3 pentagonal pyramids that share corners with three equivalent HoSi4Sb2 octahedra, corners with ten equivalent HoSi3Sb3 pentagonal pyramids, edges with seven equivalent HoSi3Sb3 pentagonal pyramids, faces with two equivalent HoSi4Sb2 octahedra, and faces with two equivalent HoSi3Sb3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 36–41°. There are a spread of Ho–Si bond distances ranging from 2.94–3.02 Å. There are a spread of Ho–Sb bond distances ranging from 3.13–3.17 Å. In the second Ho site, Ho is bonded to four equivalent Si and two equivalent Sb atoms to form HoSi4Sb2 octahedra that share corners with four equivalent HoSi4Sb2 octahedra, corners with twelve equivalent HoSi3Sb3 pentagonal pyramids, and faces with eight equivalent HoSi3Sb3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 50°. There are two shorter (3.05 Å) and two longer (3.07 Å) Ho–Si bond lengths. Both Ho–Sb bond lengths are 3.10 Å. Si is bonded in a 8-coordinate geometry to eight Ho atoms. Sb is bonded to seven Ho atoms to form a mixture of distorted edge and corner-sharing SbHo7 pentagonal bipyramids.