Materials Data on Y3BeCrS7 by Materials Project

Abstract

BeY3CrS7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Be2+ is bonded to four S2- atoms to form BeS4 tetrahedra that share corners with six equivalent YS7 pentagonal bipyramids and edges with three equivalent YS7 pentagonal bipyramids. All Be–S bond lengths are 2.10 Å. Y3+ is bonded to seven S2- atoms to form distorted YS7 pentagonal bipyramids that share a cornercorner with one CrS6 octahedra, corners with six equivalent YS7 pentagonal bipyramids, corners with two equivalent BeS4 tetrahedra, an edgeedge with one CrS6 octahedra, edges with four equivalent YS7 pentagonal bipyramids, an edgeedge with one BeS4 tetrahedra, and a faceface with one CrS6 octahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Y–S bond distances ranging from 2.67–2.98 Å. Cr3+ is bonded to six equivalent S2- atoms to form CrS6 octahedra that share corners with three equivalent YS7 pentagonal bipyramids, edges with three equivalent YS7 pentagonal bipyramids, faces with two equivalent CrS6 octahedra, and faces with three equivalent YS7 pentagonal bipyramids. There are three shorter (2.39 Å) and three longer (2.45 Å) Cr–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Y3+ and two equivalent Cr3+ atoms to form a mixture of distorted edge, corner, and face-sharing SY3Cr2 square pyramids. In the second S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Be2+ and three equivalent Y3+ atoms. In the third S2- site, S2- is bonded in a 4-coordinate geometry to one Be2+ and three equivalent Y3+ atoms.