DOI: 10.17188/1318237
title: Materials Data on Mg(InSe2)2 by Materials Project

description: Mg(InSe2)2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one Mg(InSe2)2 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share a cornercorner with one MgSe4 tetrahedra, corners with five InSe4 tetrahedra, edges with two equivalent MgSe6 octahedra, and edges with four equivalent InSe6 octahedra. There are a spread of Mg–Se bond distances ranging from 2.74–2.79 Å. In the second Mg2+ site, Mg2+ is bonded to four Se2- atoms to form MgSe4 tetrahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent InSe6 octahedra, and corners with six InSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–59°. There are a spread of Mg–Se bond distances ranging from 2.58–2.62 Å. There are four inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with two equivalent MgSe4 tetrahedra, corners with four InSe4 tetrahedra, edges with two equivalent InSe6 octahedra, and edges with four equivalent MgSe6 octahedra. There are a spread of In–Se bond distances ranging from 2.75–2.83 Å. In the second In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share a cornercorner with one InSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with two equivalent MgSe4 tetrahedra, and corners with four InSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–61°. There are a spread of In–Se bond distances ranging from 2.60–2.68 Å. In the third In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share a cornercorner with one InSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with two equivalent MgSe4 tetrahedra, and corners with four InSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–61°. There are a spread of In–Se bond distances ranging from 2.61–2.68 Å. In the fourth In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent InSe6 octahedra, corners with two equivalent MgSe4 tetrahedra, and corners with four InSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–61°. There are a spread of In–Se bond distances ranging from 2.62–2.67 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three In3+ atoms. In the second Se2- site, Se2- is bonded to two Mg2+ and two equivalent In3+ atoms to form distorted SeMg2In2 trigonal pyramids that share corners with seven SeMg2In2 tetrahedra, corners with two equivalent SeMg2In2 trigonal pyramids, an edgeedge with one SeMgIn3 tetrahedra, and edges with two SeMg2In2 trigonal pyramids. In the third Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two In3+ atoms. In the fourth Se2- site, Se2- is bonded to two equivalent Mg2+ and two In3+ atoms to form a mixture of distorted edge and corner-sharing SeMg2In2 trigonal pyramids. In the fifth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two In3+ atoms. In the sixth Se2- site, Se2- is bonded to two equivalent Mg2+ and two In3+ atoms to form distorted SeMg2In2 tetrahedra that share corners with two equivalent SeMgIn3 tetrahedra, corners with seven SeMg2In2 trigonal pyramids, edges with two SeMg2In2 tetrahedra, and an edgeedge with one SeMg2In2 trigonal pyramid. In the seventh Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two In3+ atoms. In the eighth Se2- site, Se2- is bonded to one Mg2+ and three In3+ atoms to form a mixture of distorted edge and corner-sharing SeMgIn3 tetrahedra.