Materials Data on HoMgSe3 by Materials Project
MgHoSe3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded to six Se+1.67- atoms to form MgSe6 octahedra that share corners with eight equivalent HoSe4 tetrahedra and edges with three equivalent MgSe6 octahedra. There are a spread of Mg–Se bond distances ranging from 2.67–2.96 Å. Ho3+ is bonded to four Se+1.67- atoms to form HoSe4 tetrahedra that share corners with eight equivalent MgSe6 octahedra and an edgeedge with one HoSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–76°. There are three shorter (2.71 Å) and one longer (2.73 Å) Ho–Se bond lengths. There are two inequivalent Se+1.67- sites. In the first Se+1.67- site, Se+1.67- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one Ho3+ atom. In the second Se+1.67- site, Se+1.67- is bonded to two equivalent Mg2+ and two equivalent Ho3+ atoms to form edge-sharing SeHo2Mg2 tetrahedra.