Materials Data on CaTcN3 by Materials Project

Abstract

CaTcN3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six N3- atoms to form distorted CaN6 pentagonal pyramids that share corners with four equivalent TcN4 tetrahedra, edges with three equivalent CaN6 octahedra, and edges with two equivalent TcN4 tetrahedra. There are a spread of Ca–N bond distances ranging from 2.49–2.56 Å. In the second Ca2+ site, Ca2+ is bonded to six N3- atoms to form CaN6 octahedra that share corners with six equivalent TcN4 tetrahedra, edges with two equivalent CaN6 octahedra, and edges with three equivalent CaN6 pentagonal pyramids. There are a spread of Ca–N bond distances ranging from 2.40–2.50 Å. Tc7+ is bonded to four N3- atoms to form TcN4 tetrahedra that share corners with three equivalent CaN6 octahedra, corners with two equivalent CaN6 pentagonal pyramids, corners with two equivalent TcN4 tetrahedra, and an edgeedge with one CaN6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 30–67°. There are a spread of Tc–N bond distances ranging from 1.74–1.92 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+ and two equivalent Tc7+ atoms. In the second N3- site, N3- is bonded to three Ca2+ and one Tc7+ atom to form a mixture of distorted edge and corner-sharing NCa3Tc tetrahedra. In the third N3- site, N3- is bonded in a distorted T-shaped geometry to two Ca2+ and one Tc7+ atom.