Materials Data on Ca3(CrN3)2 by Materials Project
Ca3(CrN3)2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first 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 2.37–2.53 Å. In the second Ca2+ site, Ca2+ is bonded to five N3- atoms to form a mixture of distorted edge and corner-sharing CaN5 square pyramids. There are a spread of Ca–N bond distances ranging from 2.34–2.49 Å. In the third Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to six N3- atoms. There are a spread of Ca–N bond distances ranging from 2.32–3.16 Å. There are two inequivalent Cr6+ sites. In the first Cr6+ site, Cr6+ is bonded in a trigonal planar geometry to three N3- atoms. There are a spread of Cr–N bond distances ranging from 1.67–1.73 Å. In the second Cr6+ site, Cr6+ is bonded in a trigonal planar geometry to three N3- atoms. There is one shorter (1.64 Å) and two longer (1.73 Å) Cr–N bond length. There are six inequivalent N3- sites. In the first N3- site, N3- is bonded in a 2-coordinate geometry to three Ca2+ and one Cr6+ atom. In the second N3- site, N3- is bonded in a distorted square co-planar geometry to three Ca2+ and one Cr6+ atom. In the third N3- site, N3- is bonded to four Ca2+ and one Cr6+ atom to form distorted corner-sharing NCa4Cr square pyramids. In the fourth N3- site, N3- is bonded in a bent 150 degrees geometry to one Ca2+ and one Cr6+ atom. In the fifth N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Cr6+ atom. In the sixth N3- site, N3- is bonded in a distorted trigonal planar geometry to two Ca2+ and one Cr6+ atom.