Materials Data on BiPb2F7 by Materials Project

Abstract

Pb2BiF7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pb2+ is bonded in a body-centered cubic geometry to nine F1- atoms. There are a spread of Pb–F bond distances ranging from 2.53–3.08 Å. Bi3+ is bonded to twelve F1- atoms to form distorted BiF12 cuboctahedra that share corners with four equivalent BiF12 cuboctahedra, corners with sixteen equivalent FBi2Pb2F2 tetrahedra, edges with eight equivalent FBi2Pb2F2 tetrahedra, and faces with four equivalent BiF12 cuboctahedra. There are eight shorter (2.56 Å) and four longer (2.87 Å) Bi–F bond lengths. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded to four equivalent Pb2+ atoms to form a mixture of corner and edge-sharing FPb4 tetrahedra. In the second F1- site, F1- is bonded to two equivalent Pb2+, two equivalent Bi3+, and two equivalent F1- atoms to form FBi2Pb2F2 tetrahedra that share corners with four equivalent BiF12 cuboctahedra, corners with twelve FPb4 tetrahedra, edges with two equivalent BiF12 cuboctahedra, edges with seven FPb4 tetrahedra, and faces with five equivalent FBi2Pb2F2 tetrahedra. Both F–F bond lengths are 2.56 Å. In the third F1- site, F1- is bonded in a 12-coordinate geometry to two equivalent Pb2+, four equivalent Bi3+, and eight equivalent F1- atoms.