Materials Data on SrCa3(BrN)2 by Materials Project

Abstract

SrCa3(NBr)2 is Caswellsilverite-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Sr2+ is bonded to three N3- and three Br1- atoms to form distorted SrBr3N3 octahedra that share corners with six equivalent CaBr3N3 octahedra, edges with two equivalent SrBr3N3 octahedra, and edges with six CaBr3N3 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are two shorter (2.59 Å) and one longer (2.61 Å) Sr–N bond lengths. There are one shorter (3.15 Å) and two longer (3.18 Å) Sr–Br bond lengths. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to three N3- and three Br1- atoms. There are one shorter (2.46 Å) and two longer (2.48 Å) Ca–N bond lengths. There are two shorter (3.23 Å) and one longer (3.26 Å) Ca–Br bond lengths. In the second Ca2+ site, Ca2+ is bonded to three N3- and three Br1- atoms to form distorted CaBr3N3 octahedra that share corners with six equivalent SrBr3N3 octahedra, edges with two equivalent SrBr3N3 octahedra, and edges with six CaBr3N3 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are one shorter (2.47 Å) and two longer (2.48 Å) Ca–N bond lengths. There are two shorter (3.09 Å) and one longer (3.11 Å) Ca–Br bond lengths. In the third Ca2+ site, Ca2+ is bonded to three N3- and three Br1- atoms to form distorted CaBr3N3 octahedra that share edges with four equivalent SrBr3N3 octahedra and edges with six CaBr3N3 octahedra. There are two shorter (2.51 Å) and one longer (2.53 Å) Ca–N bond lengths. There are one shorter (3.13 Å) and two longer (3.15 Å) Ca–Br bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to two equivalent Sr2+ and four Ca2+ atoms to form edge-sharing NSr2Ca4 octahedra. In the second N3- site, N3- is bonded to one Sr2+ and five Ca2+ atoms to form edge-sharing NSrCa5 octahedra. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 6-coordinate geometry to two equivalent Sr2+ and four Ca2+ atoms. In the second Br1- site, Br1- is bonded in a 6-coordinate geometry to one Sr2+ and five Ca2+ atoms.