Materials Data on Sr5Cd2Sb5F by Materials Project

Abstract

Sr5Cd2Sb5F crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a distorted bent 120 degrees geometry to six Sb+2.60- and two equivalent F1- atoms. There are two shorter (3.60 Å) and four longer (3.65 Å) Sr–Sb bond lengths. Both Sr–F bond lengths are 2.71 Å. In the second Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six Sb+2.60- atoms. There are two shorter (3.43 Å) and four longer (3.48 Å) Sr–Sb bond lengths. In the third Sr2+ site, Sr2+ is bonded in a distorted single-bond geometry to five Sb+2.60- and one F1- atom. There are a spread of Sr–Sb bond distances ranging from 3.34–3.45 Å. The Sr–F bond length is 2.54 Å. In the fourth Sr2+ site, Sr2+ is bonded to six Sb+2.60- atoms to form SrSb6 octahedra that share edges with two equivalent SrSb6 octahedra and edges with four equivalent CdSb4 tetrahedra. There are four shorter (3.33 Å) and two longer (3.36 Å) Sr–Sb bond lengths. Cd2+ is bonded to four Sb+2.60- atoms to form CdSb4 tetrahedra that share corners with three equivalent CdSb4 tetrahedra and edges with two equivalent SrSb6 octahedra. There are a spread of Cd–Sb bond distances ranging from 2.90–3.01 Å. There are three inequivalent Sb+2.60- sites. In the first Sb+2.60- site, Sb+2.60- is bonded in a 8-coordinate geometry to six Sr2+ and two equivalent Cd2+ atoms. In the second Sb+2.60- site, Sb+2.60- is bonded in a 7-coordinate geometry to five Sr2+ and two equivalent Cd2+ atoms. In the third Sb+2.60- site, Sb+2.60- is bonded in a 8-coordinate geometry to six Sr2+, one Cd2+, and one Sb+2.60- atom. The Sb–Sb bond length is 2.86 Å. F1- is bonded to four Sr2+ atoms to form corner-sharing FSr4 tetrahedra.