Materials Data on Na4Mg(GeSe3)2 by Materials Project

Abstract

Na4Mg(GeSe3)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with six NaSe6 octahedra, edges with three equivalent MgSe6 octahedra, and edges with six NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 6–13°. There are a spread of Na–Se bond distances ranging from 3.03–3.12 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with two equivalent MgSe6 octahedra, edges with two equivalent MgSe6 octahedra, and edges with eight NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 7–13°. There are a spread of Na–Se bond distances ranging from 3.05–3.16 Å. In the third Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with two equivalent MgSe6 octahedra, edges with two equivalent MgSe6 octahedra, and edges with eight NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 6–7°. There are a spread of Na–Se bond distances ranging from 2.99–3.15 Å. In the fourth Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with two equivalent MgSe6 octahedra, edges with two equivalent MgSe6 octahedra, and edges with eight NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Na–Se bond distances ranging from 2.97–3.05 Å. Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share corners with six NaSe6 octahedra and edges with nine NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°. There are a spread of Mg–Se bond distances ranging from 2.79–2.86 Å. Ge3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.38 Å) and one longer (2.41 Å) Ge–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Na1+, one Mg2+, and one Ge3+ atom to form a mixture of edge and corner-sharing SeNa4MgGe octahedra. The corner-sharing octahedra tilt angles range from 4–85°. In the second Se2- site, Se2- is bonded to four Na1+, one Mg2+, and one Ge3+ atom to form a mixture of edge and corner-sharing SeNa4MgGe octahedra. The corner-sharing octahedra tilt angles range from 4–85°. In the third Se2- site, Se2- is bonded to four Na1+, one Mg2+, and one Ge3+ atom to form a mixture of edge and corner-sharing SeNa4MgGe octahedra. The corner-sharing octahedra tilt angles range from 1–85°.