DOE OSTI2020
Mg2SnN2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five N3- atoms to form distorted MgN5 square pyramids that share corners with two equivalent MgN5 square pyramids, corners with two MgN4 trigonal pyramids, edges with three equivalent MgN5 square pyramids, and edges with four MgN4 trigonal pyramids. There are a spread of Mg–N bond distances ranging from 2.13–2.73 Å. In the second Mg2+ site, Mg2+ is bonded to five N3- atoms to form distorted MgN5 square pyramids that share corners with two equivalent MgN5 square pyramids, corners with two MgN4 trigonal pyramids, edges with three equivalent MgN5 square pyramids, and edges with four MgN4 trigonal pyramids. There are a spread of Mg–N bond distances ranging from 2.14–2.72 Å. In the third Mg2+ site, Mg2+ is bonded to four N3- atoms to form MgN4 trigonal pyramids that share corners with two MgN5 square pyramids, corners with two equivalent MgN4 trigonal pyramids, edges with four MgN5 square pyramids, and an edgeedge with one MgN4 trigonal pyramid. There are a spread of Mg–N bond distances ranging from 2.10–2.21 Å. In the fourth Mg2+ site, Mg2+ is bonded to four N3- atoms to form MgN4 trigonal pyramids that share corners with two MgN5 square pyramids, corners with two equivalent MgN4 trigonal pyramids, edges with four MgN5 square pyramids, and an edgeedge with one MgN4 trigonal pyramid. There are a spread of Mg–N bond distances ranging from 2.10–2.21 Å. There are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded in a T-shaped geometry to three N3- atoms. There are a spread of Sn–N bond distances ranging from 2.19–2.35 Å. In the second Sn2+ site, Sn2+ is bonded in a T-shaped geometry to three N3- atoms. There are a spread of Sn–N bond distances ranging from 2.19–2.35 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to five Mg2+ and one Sn2+ atom to form a mixture of edge and corner-sharing NMg5Sn octahedra. The corner-sharing octahedra tilt angles range from 11–17°. In the second N3- site, N3- is bonded to five Mg2+ and one Sn2+ atom to form a mixture of edge and corner-sharing NMg5Sn octahedra. The corner-sharing octahedra tilt angles range from 10–17°. In the third N3- site, N3- is bonded to four Mg2+ and two Sn2+ atoms to form a mixture of distorted edge and corner-sharing NMg4Sn2 octahedra. The corner-sharing octahedra tilt angles range from 11–26°. In the fourth N3- site, N3- is bonded to four Mg2+ and two Sn2+ atoms to form a mixture of distorted edge and corner-sharing NMg4Sn2 octahedra. The corner-sharing octahedra tilt angles range from 10–27°.