Materials Data on LaMgSe3 by Materials Project
MgLaSe3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded to six Se+1.67- atoms to form distorted MgSe6 octahedra that share corners with eight equivalent LaSe4 tetrahedra and edges with three equivalent MgSe6 octahedra. There are a spread of Mg–Se bond distances ranging from 2.64–3.16 Å. La3+ is bonded to four Se+1.67- atoms to form distorted LaSe4 tetrahedra that share corners with eight equivalent MgSe6 octahedra and an edgeedge with one LaSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–77°. There are a spread of La–Se bond distances ranging from 2.86–2.89 Å. There are two inequivalent Se+1.67- sites. In the first Se+1.67- site, Se+1.67- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and one La3+ atom. In the second Se+1.67- site, Se+1.67- is bonded to two equivalent Mg2+ and two equivalent La3+ atoms to form edge-sharing SeLa2Mg2 tetrahedra.