Materials Data on Mg(InSe2)2 by Materials Project

Abstract

Mg(InSe2)2 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three Mg(InSe2)2 sheets oriented in the (0, 0, 1) direction. Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share corners with six InSe4 tetrahedra and edges with six equivalent MgSe6 octahedra. There are three shorter (2.74 Å) and three longer (2.75 Å) Mg–Se bond lengths. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with three equivalent MgSe6 octahedra and corners with six equivalent InSe4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are one shorter (2.54 Å) and three longer (2.69 Å) In–Se bond lengths. In the second In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with three equivalent MgSe6 octahedra and corners with six equivalent InSe4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are one shorter (2.54 Å) and three longer (2.69 Å) In–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent In3+ atoms. In the second Se2- site, Se2- is bonded to three equivalent Mg2+ and one In3+ atom to form a mixture of distorted corner and edge-sharing SeMg3In tetrahedra. In the third Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent In3+ atoms. In the fourth Se2- site, Se2- is bonded to three equivalent Mg2+ and one In3+ atom to form a mixture of distorted corner and edge-sharing SeMg3In tetrahedra.