Materials Data on K2Ge2PbS6 by Materials Project

Abstract

K2PbGe2S6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.32–3.57 Å. Pb2+ is bonded to six S2- atoms to form distorted PbS6 pentagonal pyramids that share corners with two equivalent GeS4 tetrahedra, edges with two equivalent PbS6 pentagonal pyramids, and edges with two equivalent GeS4 tetrahedra. There are a spread of Pb–S bond distances ranging from 2.89–3.21 Å. Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share a cornercorner with one PbS6 pentagonal pyramid, an edgeedge with one PbS6 pentagonal pyramid, and an edgeedge with one GeS4 tetrahedra. There are a spread of Ge–S bond distances ranging from 2.19–2.30 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to three equivalent K1+, one Pb2+, and one Ge4+ atom. In the second S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Ge4+ atoms. In the third S2- site, S2- is bonded in a 1-coordinate geometry to two equivalent K1+, two equivalent Pb2+, and one Ge4+ atom.