Materials Data on Ca4TiN4 by Materials Project
Ca4TiN4 crystallizes in the triclinic P-1 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 CaN5 square pyramids that share corners with three equivalent CaN5 square pyramids, a cornercorner with one TiN4 tetrahedra, corners with two equivalent CaN4 trigonal pyramids, edges with five CaN5 square pyramids, and edges with two equivalent TiN4 tetrahedra. There are a spread of Ca–N bond distances ranging from 2.44–2.59 Å. In the second Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Ca–N bond distances ranging from 2.42–2.86 Å. In the third Ca2+ site, Ca2+ is bonded to four N3- atoms to form distorted CaN4 trigonal pyramids that share corners with four CaN5 square pyramids, corners with four equivalent TiN4 tetrahedra, and edges with two equivalent CaN4 trigonal pyramids. There are a spread of Ca–N bond distances ranging from 2.40–2.49 Å. In the fourth Ca2+ site, Ca2+ is bonded to five N3- atoms to form CaN5 square pyramids that share corners with three equivalent CaN5 square pyramids, corners with three equivalent TiN4 tetrahedra, corners with two equivalent CaN4 trigonal pyramids, edges with five CaN5 square pyramids, and an edgeedge with one TiN4 tetrahedra. There are a spread of Ca–N bond distances ranging from 2.41–2.50 Å. Ti4+ is bonded to four N3- atoms to form TiN4 tetrahedra that share corners with four CaN5 square pyramids, corners with four equivalent CaN4 trigonal pyramids, and edges with three CaN5 square pyramids. There are a spread of Ti–N bond distances ranging from 1.94–1.98 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to five Ca2+ and one Ti4+ atom to form a mixture of corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedra tilt angles range from 6–20°. In the second N3- site, N3- is bonded to five Ca2+ and one Ti4+ atom to form a mixture of distorted corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedra tilt angles range from 6–20°. In the third N3- site, N3- is bonded to five Ca2+ and one Ti4+ atom to form a mixture of corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedra tilt angles range from 11–16°. In the fourth N3- site, N3- is bonded in a 5-coordinate geometry to four Ca2+ and one Ti4+ atom.