DOI: 10.17188/1282764
title: Materials Data on Ca(Bi2O3)2 by Materials Project

description: Ca(Bi2O3)2 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of one Ca(Bi2O3)2 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share a cornercorner with one BiO5 square pyramid, corners with three BiO4 trigonal pyramids, edges with two equivalent CaO7 hexagonal pyramids, an edgeedge with one CaO6 octahedra, and edges with two equivalent BiO5 square pyramids. There are a spread of Ca–O bond distances ranging from 2.33–2.84 Å. In the second Ca2+ site, Ca2+ is bonded to seven O2- atoms to form distorted CaO7 hexagonal pyramids that share corners with three BiO4 trigonal pyramids, edges with four equivalent CaO6 octahedra, and edges with two equivalent BiO5 square pyramids. There are a spread of Ca–O bond distances ranging from 2.43–2.66 Å. There are seven inequivalent Bi+2.50+ sites. In the first Bi+2.50+ site, Bi+2.50+ is bonded to four O2- atoms to form BiO4 trigonal pyramids that share a cornercorner with one CaO7 hexagonal pyramid, corners with two equivalent CaO6 octahedra, and corners with six BiO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 66°. There are a spread of Bi–O bond distances ranging from 2.08–2.34 Å. In the second Bi+2.50+ site, Bi+2.50+ is bonded in a T-shaped geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.19–2.43 Å. In the third Bi+2.50+ site, Bi+2.50+ is bonded to four O2- atoms to form BiO4 trigonal pyramids that share a cornercorner with one CaO7 hexagonal pyramid, a cornercorner with one CaO6 octahedra, a cornercorner with one BiO5 square pyramid, and corners with six BiO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 70°. There are a spread of Bi–O bond distances ranging from 2.15–2.29 Å. In the fourth Bi+2.50+ site, Bi+2.50+ is bonded in an L-shaped geometry to two O2- atoms. There are one shorter (2.13 Å) and one longer (2.18 Å) Bi–O bond lengths. In the fifth Bi+2.50+ site, Bi+2.50+ is bonded to four O2- atoms to form BiO4 trigonal pyramids that share a cornercorner with one CaO6 octahedra, corners with two equivalent BiO5 square pyramids, and corners with six BiO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 59°. There are a spread of Bi–O bond distances ranging from 2.09–2.37 Å. In the sixth Bi+2.50+ site, Bi+2.50+ is bonded to five O2- atoms to form distorted BiO5 square pyramids that share a cornercorner with one CaO6 octahedra, corners with two equivalent BiO5 square pyramids, corners with three BiO4 trigonal pyramids, an edgeedge with one CaO7 hexagonal pyramid, and edges with two equivalent CaO6 octahedra. The corner-sharing octahedral tilt angles are 78°. There are a spread of Bi–O bond distances ranging from 2.22–2.92 Å. In the seventh Bi+2.50+ site, Bi+2.50+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.13–2.49 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two Bi+2.50+ atoms to form OCa2Bi2 tetrahedra that share corners with three OCa2Bi2 tetrahedra, an edgeedge with one OCa3Bi tetrahedra, and an edgeedge with one OCaBi3 trigonal pyramid. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Bi+2.50+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Bi+2.50+ atoms. In the fourth O2- site, O2- is bonded to three Ca2+ and one Bi+2.50+ atom to form OCa3Bi tetrahedra that share corners with five OCa2Bi2 tetrahedra, an edgeedge with one OCa3Bi tetrahedra, and an edgeedge with one OCaBi3 trigonal pyramid. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three Bi+2.50+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Bi+2.50+ atoms. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to three Bi+2.50+ atoms. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to three Bi+2.50+ atoms. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to one Ca2+ and two Bi+2.50+ atoms. In the tenth O2- site, O2- is bonded to one Ca2+ and three Bi+2.50+ atoms to form distorted OCaBi3 trigonal pyramids that share a cornercorner with one OCa3Bi tetrahedra and edges with three OCa2Bi2 tetrahedra. In the eleventh O2- site, O2- is bonded to three Ca2+ and one Bi+2.50+ atom to form distorted OCa3Bi tetrahedra that share a cornercorner with one OCa3Bi tetrahedra, a cornercorner with one OCaBi3 trigonal pyramid, and edges with three OCa2Bi2 tetrahedra.