DOI: 10.17188/1719211
title: Materials Data on Ho2MgS4 by Materials Project

description: MgHo2S4 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one MgHo2S4 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four S2- atoms to form MgS4 tetrahedra that share a cornercorner with one MgS6 octahedra, corners with two equivalent HoS6 octahedra, and corners with six HoS4 tetrahedra. The corner-sharing octahedra tilt angles range from 60–61°. There are a spread of Mg–S bond distances ranging from 2.43–2.47 Å. In the second Mg2+ site, Mg2+ is bonded to six S2- atoms to form MgS6 octahedra that share a cornercorner with one MgS4 tetrahedra, corners with five HoS4 tetrahedra, edges with two equivalent MgS6 octahedra, and edges with four equivalent HoS6 octahedra. There are a spread of Mg–S bond distances ranging from 2.68–2.75 Å. There are four inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to four S2- atoms to form HoS4 tetrahedra that share a cornercorner with one HoS6 octahedra, corners with two equivalent MgS6 octahedra, corners with two equivalent MgS4 tetrahedra, and corners with four HoS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–62°. There are one shorter (2.56 Å) and three longer (2.59 Å) Ho–S bond lengths. In the second Ho3+ site, Ho3+ is bonded to six S2- atoms to form HoS6 octahedra that share corners with two equivalent MgS4 tetrahedra, corners with four HoS4 tetrahedra, edges with two equivalent HoS6 octahedra, and edges with four equivalent MgS6 octahedra. There are a spread of Ho–S bond distances ranging from 2.73–2.82 Å. In the third Ho3+ site, Ho3+ is bonded to four S2- atoms to form HoS4 tetrahedra that share a cornercorner with one HoS6 octahedra, corners with two equivalent MgS6 octahedra, corners with two equivalent MgS4 tetrahedra, and corners with four HoS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–65°. There are a spread of Ho–S bond distances ranging from 2.56–2.59 Å. In the fourth Ho3+ site, Ho3+ is bonded to four S2- atoms to form HoS4 tetrahedra that share a cornercorner with one MgS6 octahedra, corners with two equivalent HoS6 octahedra, corners with two equivalent MgS4 tetrahedra, and corners with four HoS4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–63°. There are two shorter (2.57 Å) and two longer (2.58 Å) Ho–S bond lengths. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Mg2+ and two Ho3+ atoms to form a mixture of distorted edge and corner-sharing SHo2Mg2 tetrahedra. In the second S2- site, S2- is bonded to two Mg2+ and two equivalent Ho3+ atoms to form distorted SHo2Mg2 tetrahedra that share corners with nine SHo2Mg2 tetrahedra and edges with three SHo3Mg tetrahedra. In the third S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Ho3+ atoms. In the fourth S2- site, S2- is bonded in a trigonal non-coplanar geometry to three Ho3+ atoms. In the fifth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Ho3+ atoms. In the sixth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Ho3+ atoms. In the seventh S2- site, S2- is bonded to one Mg2+ and three Ho3+ atoms to form distorted SHo3Mg tetrahedra that share corners with nine SHo2Mg2 tetrahedra and edges with three SHo3Mg tetrahedra. In the eighth S2- site, S2- is bonded to two equivalent Mg2+ and two Ho3+ atoms to form distorted SHo2Mg2 tetrahedra that share corners with nine SHo2Mg2 tetrahedra and edges with three SHo3Mg tetrahedra.