Materials Data on Mg(ScS2)2 by Materials Project

Abstract

Mg(ScS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded to seven S2- atoms to form distorted MgS7 pentagonal bipyramids that share corners with eight ScS6 octahedra, edges with five ScS6 octahedra, edges with two equivalent MgS7 pentagonal bipyramids, and faces with two equivalent MgS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–65°. There are a spread of Mg–S bond distances ranging from 2.62–2.99 Å. There are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six S2- atoms to form ScS6 octahedra that share corners with three equivalent ScS6 octahedra, corners with four equivalent MgS7 pentagonal bipyramids, edges with six ScS6 octahedra, and an edgeedge with one MgS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Sc–S bond distances ranging from 2.55–2.66 Å. In the second Sc3+ site, Sc3+ is bonded to six S2- atoms to form ScS6 octahedra that share corners with three equivalent ScS6 octahedra, corners with four equivalent MgS7 pentagonal bipyramids, edges with four ScS6 octahedra, and edges with four equivalent MgS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Sc–S bond distances ranging from 2.56–2.64 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Mg2+ and two equivalent Sc3+ atoms to form a mixture of corner and edge-sharing SMg3Sc2 square pyramids. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Sc3+ atoms. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Mg2+ and three Sc3+ atoms. In the fourth S2- site, S2- is bonded to two equivalent Mg2+ and three Sc3+ atoms to form SMg2Sc3 square pyramids that share corners with two equivalent SMg3Sc2 square pyramids and edges with five SMg2Sc3 square pyramids.