Materials Data on Si2Pb3O7 by Materials Project
Pb3Si2O7 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six equivalent O2- atoms to form distorted PbO6 pentagonal pyramids that share corners with six equivalent SiO4 tetrahedra. All Pb–O bond lengths are 2.52 Å. In the second Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six O2- atoms. All Pb–O bond lengths are 2.65 Å. In the third Pb2+ site, Pb2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Pb–O bond distances ranging from 2.22–2.93 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one PbO6 pentagonal pyramid and a cornercorner with one SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three Pb2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Pb2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Pb2+ and one Si4+ atom.