Materials Data on KPb2Br5 by Materials Project

Abstract

KPb2Br5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight Br1- atoms. There are a spread of K–Br bond distances ranging from 3.47–3.60 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 7-coordinate geometry to seven Br1- atoms. There are a spread of Pb–Br bond distances ranging from 3.01–3.53 Å. In the second Pb2+ site, Pb2+ is bonded to seven Br1- atoms to form distorted edge-sharing PbBr7 pentagonal bipyramids. There are a spread of Pb–Br bond distances ranging from 3.00–3.40 Å. There are five inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Pb2+ atoms. In the second Br1- site, Br1- is bonded to two equivalent K1+ and two Pb2+ atoms to form BrK2Pb2 trigonal pyramids that share corners with five equivalent BrK2Pb3 trigonal bipyramids, corners with six BrK2Pb2 trigonal pyramids, an edgeedge with one BrK2Pb3 trigonal bipyramid, and edges with three BrK2Pb2 trigonal pyramids. In the third Br1- site, Br1- is bonded to two equivalent K1+ and three Pb2+ atoms to form distorted BrK2Pb3 trigonal bipyramids that share corners with thirteen BrK2Pb2 trigonal pyramids, edges with two equivalent BrK2Pb3 trigonal bipyramids, and edges with three BrK2Pb2 trigonal pyramids. In the fourth Br1- site, Br1- is bonded to four Pb2+ atoms to form distorted BrPb4 trigonal pyramids that share corners with four equivalent BrK2Pb3 trigonal bipyramids, corners with eight BrK2Pb2 trigonal pyramids, an edgeedge with one BrK2Pb3 trigonal bipyramid, and edges with two BrK2Pb2 trigonal pyramids. In the fifth Br1- site, Br1- is bonded to two equivalent K1+ and two equivalent Pb2+ atoms to form distorted BrK2Pb2 trigonal pyramids that share corners with four equivalent BrK2Pb3 trigonal bipyramids, corners with eight BrK2Pb2 trigonal pyramids, an edgeedge with one BrK2Pb3 trigonal bipyramid, and edges with three BrK2Pb2 trigonal pyramids.