Materials Data on Sr(ErSe2)2 by Materials Project
Sr(ErSe2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Sr–Se bond distances ranging from 3.21–3.45 Å. There are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Er–Se bond distances ranging from 2.82–2.88 Å. In the second Er3+ site, Er3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Er–Se bond distances ranging from 2.80–2.89 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Er3+ atoms. In the second Se2- site, Se2- is bonded to two equivalent Sr2+ and three equivalent Er3+ atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 square pyramids. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Er3+ atoms. In the fourth Se2- site, Se2- is bonded to two equivalent Sr2+ and three equivalent Er3+ atoms to form a mixture of distorted corner and edge-sharing SeSr2Er3 trigonal bipyramids.