DOE OSTI2020
Pb7F12Cl2 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 5-coordinate geometry to two equivalent Cl1- and five F1- atoms. Both Pb–Cl bond lengths are 3.18 Å. There are a spread of Pb–F bond distances ranging from 2.42–2.80 Å. In the second Pb2+ site, Pb2+ is bonded in a 7-coordinate geometry to two equivalent Cl1- and seven F1- atoms. Both Pb–Cl bond lengths are 3.30 Å. There are a spread of Pb–F bond distances ranging from 2.42–2.80 Å. In the third Pb2+ site, Pb2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are three shorter (2.54 Å) and six longer (2.75 Å) Pb–F bond lengths. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 6-coordinate geometry to six equivalent Pb2+ and nine F1- atoms. There are three shorter (3.42 Å) and six longer (3.44 Å) Cl–F bond lengths. In the second Cl1- site, Cl1- is bonded in a 12-coordinate geometry to six equivalent Pb2+ atoms. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to three Pb2+ atoms. In the second F1- site, F1- is bonded to four Pb2+ and two equivalent Cl1- atoms to form a mixture of edge, corner, and face-sharing FPb4Cl2 tetrahedra. In the third F1- site, F1- is bonded to four Pb2+ atoms to form a mixture of edge and corner-sharing FPb4 tetrahedra. In the fourth F1- site, F1- is bonded to four Pb2+ and one Cl1- atom to form a mixture of distorted edge, corner, and face-sharing FPb4Cl tetrahedra.