Materials Data on Er5(SiSb)2 by Materials Project
Er5(SiSb)2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Er sites. In the first Er site, Er is bonded to three equivalent Si and three equivalent Sb atoms to form distorted ErSi3Sb3 pentagonal pyramids that share corners with three equivalent ErSi4Sb2 octahedra, corners with ten equivalent ErSi3Sb3 pentagonal pyramids, edges with seven equivalent ErSi3Sb3 pentagonal pyramids, faces with two equivalent ErSi4Sb2 octahedra, and faces with two equivalent ErSi3Sb3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 36–41°. There are a spread of Er–Si bond distances ranging from 2.91–3.01 Å. There are a spread of Er–Sb bond distances ranging from 3.11–3.15 Å. In the second Er site, Er is bonded to four equivalent Si and two equivalent Sb atoms to form ErSi4Sb2 octahedra that share corners with four equivalent ErSi4Sb2 octahedra, corners with twelve equivalent ErSi3Sb3 pentagonal pyramids, and faces with eight equivalent ErSi3Sb3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 50°. There are two shorter (3.02 Å) and two longer (3.04 Å) Er–Si bond lengths. Both Er–Sb bond lengths are 3.08 Å. Si is bonded in a 8-coordinate geometry to eight Er atoms. Sb is bonded to seven Er atoms to form a mixture of distorted edge and corner-sharing SbEr7 pentagonal bipyramids.