Materials Data on K2Pb3C3O9F2 by Materials Project
K2Pb3C3O9F2 crystallizes in the hexagonal P6_3/mmc space group. The structure is two-dimensional and consists of two K2Pb3C3O9F2 sheets oriented in the (0, 0, 1) direction. K1+ is bonded in a 9-coordinate geometry to six O2- and three equivalent F1- atoms. There are three shorter (2.76 Å) and three longer (2.91 Å) K–O bond lengths. All K–F bond lengths are 3.11 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six equivalent O2- and two equivalent F1- atoms to form corner-sharing PbO6F2 hexagonal bipyramids. All Pb–O bond lengths are 2.70 Å. Both Pb–F bond lengths are 2.46 Å. In the second Pb2+ site, Pb2+ is bonded in a distorted single-bond geometry to one F1- atom. The Pb–F bond length is 2.31 Å. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All C–O bond lengths are 1.30 Å. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All C–O bond lengths are 1.30 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+, two equivalent Pb2+, and one C4+ atom. F1- is bonded to three equivalent K1+ and two Pb2+ atoms to form distorted corner-sharing FK3Pb2 trigonal bipyramids.