DOI: 10.17188/1666953
title: Materials Data on Sr4Cu2Bi4O13 by Materials Project

description: Sr4Cu2Bi4O13 crystallizes in the monoclinic C2 space group. The structure is two-dimensional and consists of two Sr4Cu2Bi4O13 sheets oriented in the (0, 1, 0) direction. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.52–2.90 Å. In the second Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.43–3.14 Å. Cu2+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with four equivalent CuO6 octahedra and a cornercorner with one BiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 3–12°. There are a spread of Cu–O bond distances ranging from 1.96–2.67 Å. There are two inequivalent Bi+3.50+ sites. In the first Bi+3.50+ site, Bi+3.50+ is bonded to four O2- atoms to form BiO4 trigonal pyramids that share a cornercorner with one CuO6 octahedra and corners with three equivalent BiO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 23°. There are a spread of Bi–O bond distances ranging from 2.11–2.20 Å. In the second Bi+3.50+ site, Bi+3.50+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.06–2.11 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Bi+3.50+ atoms. In the second O2- site, O2- is bonded to four Sr2+ and two equivalent Cu2+ atoms to form distorted OSr4Cu2 octahedra that share corners with two equivalent OSr4Cu2 octahedra, corners with two equivalent OSr2Bi2 tetrahedra, edges with two equivalent OSr4Cu2 octahedra, and faces with two equivalent OSr4Cu2 octahedra. The corner-sharing octahedral tilt angles are 5°. In the third O2- site, O2- is bonded to four Sr2+ and two equivalent Cu2+ atoms to form distorted OSr4Cu2 octahedra that share corners with two equivalent OSr2Bi2 tetrahedra and faces with four OSr4Cu2 octahedra. In the fourth O2- site, O2- is bonded to four Sr2+ and two equivalent Cu2+ atoms to form distorted OSr4Cu2 octahedra that share corners with two equivalent OSr4Cu2 octahedra, edges with two equivalent OSr4Cu2 octahedra, an edgeedge with one OSr2Bi2 tetrahedra, and faces with two equivalent OSr4Cu2 octahedra. The corner-sharing octahedral tilt angles are 5°. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two equivalent Cu2+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+, one Cu2+, and one Bi+3.50+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Sr2+, one Cu2+, and one Bi+3.50+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Bi+3.50+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two equivalent Bi+3.50+ atoms. In the tenth O2- site, O2- is bonded to two equivalent Sr2+ and two equivalent Bi+3.50+ atoms to form a mixture of distorted edge and corner-sharing OSr2Bi2 tetrahedra. The corner-sharing octahedra tilt angles range from 4–62°. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Bi+3.50+ atoms.