DOE OSTI2020
Ca5(MnN3)2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are five inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to five N3- atoms to form a mixture of edge and corner-sharing CaN5 square pyramids. There are a spread of Ca–N bond distances ranging from 2.42–2.54 Å. In the second Ca2+ site, Ca2+ is bonded to five N3- atoms to form a mixture of edge and corner-sharing CaN5 square pyramids. There are a spread of Ca–N bond distances ranging from 2.38–2.79 Å. In the third Ca2+ site, Ca2+ is bonded to five N3- atoms to form a mixture of distorted edge and corner-sharing CaN5 trigonal bipyramids. There are a spread of Ca–N bond distances ranging from 2.38–2.68 Å. In the fourth Ca2+ site, Ca2+ is bonded to five N3- atoms to form a mixture of edge and corner-sharing CaN5 square pyramids. There are a spread of Ca–N bond distances ranging from 2.40–2.63 Å. In the fifth 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 2.40–3.00 Å. There are two inequivalent Mn4+ sites. In the first Mn4+ site, Mn4+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of Mn–N bond distances ranging from 1.66–1.81 Å. In the second Mn4+ site, Mn4+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of Mn–N bond distances ranging from 1.71–1.74 Å. There are six inequivalent N3- sites. In the first N3- site, N3- is bonded in a 1-coordinate geometry to five Ca2+ and one Mn4+ atom. In the second N3- site, N3- is bonded to four Ca2+ and one Mn4+ atom to form NCa4Mn square pyramids that share corners with two equivalent NCa4Mn square pyramids, corners with two NCa4Mn trigonal bipyramids, edges with two equivalent NCa5Mn octahedra, and edges with two NCa4Mn trigonal bipyramids. In the third N3- site, N3- is bonded to five Ca2+ and one Mn4+ atom to form NCa5Mn octahedra that share corners with two equivalent NCa5Mn octahedra, edges with two equivalent NCa4Mn square pyramids, and edges with four NCa4Mn trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°. In the fourth N3- site, N3- is bonded to four Ca2+ and one Mn4+ atom to form distorted NCa4Mn trigonal bipyramids that share a cornercorner with one NCa4Mn square pyramid, corners with five NCa4Mn trigonal bipyramids, edges with two equivalent NCa5Mn octahedra, and an edgeedge with one NCa4Mn square pyramid. In the fifth N3- site, N3- is bonded to four Ca2+ and one Mn4+ atom to form distorted NCa4Mn trigonal bipyramids that share a cornercorner with one NCa4Mn square pyramid, corners with five NCa4Mn trigonal bipyramids, edges with two equivalent NCa5Mn octahedra, and an edgeedge with one NCa4Mn square pyramid. In the sixth N3- site, N3- is bonded in a 4-coordinate geometry to three Ca2+ and one Mn4+ atom.