Materials Data on Er3GaCoS7 by Materials Project

Abstract

Er3CoGaS7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share a cornercorner with one CoS6 octahedra, corners with six equivalent ErS7 pentagonal bipyramids, corners with two equivalent GaS4 tetrahedra, an edgeedge with one CoS6 octahedra, edges with four equivalent ErS7 pentagonal bipyramids, an edgeedge with one GaS4 tetrahedra, and a faceface with one CoS6 octahedra. The corner-sharing octahedral tilt angles are 24°. There are a spread of Er–S bond distances ranging from 2.71–2.97 Å. Co2+ is bonded to six equivalent S2- atoms to form CoS6 octahedra that share corners with three equivalent ErS7 pentagonal bipyramids, edges with three equivalent ErS7 pentagonal bipyramids, faces with two equivalent CoS6 octahedra, and faces with three equivalent ErS7 pentagonal bipyramids. There are three shorter (2.38 Å) and three longer (2.44 Å) Co–S bond lengths. Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with six equivalent ErS7 pentagonal bipyramids and edges with three equivalent ErS7 pentagonal bipyramids. There are one shorter (2.25 Å) and three longer (2.28 Å) Ga–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Ga3+ atom. In the second S2- site, S2- is bonded to three equivalent Er3+ and one Ga3+ atom to form distorted corner-sharing SEr3Ga tetrahedra. In the third S2- site, S2- is bonded to three equivalent Er3+ and two equivalent Co2+ atoms to form distorted SEr3Co2 square pyramids that share corners with two equivalent SEr3Co2 square pyramids, corners with three equivalent SEr3Ga tetrahedra, edges with four equivalent SEr3Co2 square pyramids, and faces with two equivalent SEr3Co2 square pyramids.