Materials Data on Ca4GeN4 by Materials Project

Abstract

Ca4GeN4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to five N3- atoms to form distorted CaN5 trigonal bipyramids that share corners with three equivalent CaN5 square pyramids, corners with three equivalent GeN4 tetrahedra, corners with six CaN5 trigonal bipyramids, an edgeedge with one GeN4 tetrahedra, edges with four CaN5 trigonal bipyramids, and a faceface with one CaN5 square pyramid. There are a spread of Ca–N bond distances ranging from 2.42–2.67 Å. In the second Ca2+ site, Ca2+ is bonded to five N3- atoms to form distorted CaN5 trigonal bipyramids that share corners with three equivalent CaN5 square pyramids, corners with three equivalent GeN4 tetrahedra, corners with seven CaN5 trigonal bipyramids, an edgeedge with one CaN5 square pyramid, an edgeedge with one GeN4 tetrahedra, and edges with four CaN5 trigonal bipyramids. There are a spread of Ca–N bond distances ranging from 2.34–2.62 Å. In the third Ca2+ site, Ca2+ is bonded to five N3- atoms to form distorted CaN5 square pyramids that share corners with two equivalent CaN5 square pyramids, a cornercorner with one GeN4 tetrahedra, corners with nine CaN5 trigonal bipyramids, edges with two equivalent GeN4 tetrahedra, edges with three CaN5 trigonal bipyramids, and a faceface with one CaN5 trigonal bipyramid. There are a spread of Ca–N bond distances ranging from 2.41–2.77 Å. In the fourth Ca2+ site, Ca2+ is bonded to five N3- atoms to form CaN5 trigonal bipyramids that share corners with three equivalent CaN5 square pyramids, a cornercorner with one GeN4 tetrahedra, corners with five CaN5 trigonal bipyramids, edges with two equivalent CaN5 square pyramids, edges with two equivalent GeN4 tetrahedra, and edges with four CaN5 trigonal bipyramids. There are a spread of Ca–N bond distances ranging from 2.40–2.53 Å. Ge4+ is bonded to four N3- atoms to form GeN4 tetrahedra that share a cornercorner with one CaN5 square pyramid, corners with seven CaN5 trigonal bipyramids, edges with two equivalent CaN5 square pyramids, and edges with four CaN5 trigonal bipyramids. There are a spread of Ge–N bond distances ranging from 1.90–1.97 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to five Ca2+ and one Ge4+ atom to form a mixture of distorted edge, face, and corner-sharing NCa5Ge octahedra. The corner-sharing octahedra tilt angles range from 16–57°. In the second N3- site, N3- is bonded in a 6-coordinate geometry to five Ca2+ and one Ge4+ atom. In the third N3- site, N3- is bonded in a 6-coordinate geometry to five Ca2+ and one Ge4+ atom. In the fourth N3- site, N3- is bonded to five Ca2+ and one Ge4+ atom to form a mixture of distorted edge, face, and corner-sharing NCa5Ge octahedra. The corner-sharing octahedra tilt angles range from 16–66°.