Materials Data on Ca2Si3PbO9 by Materials Project
Ca2PbSi3O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.80 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six SiO4 tetrahedra and an edgeedge with one CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.51 Å. Pb2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Pb–O bond distances ranging from 2.34–3.07 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent CaO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–61°. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There is two shorter (1.62 Å) and two longer (1.69 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent CaO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–61°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+, one Pb2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, two equivalent Pb2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Pb2+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ca2+, one Pb2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+, one Pb2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+, one Pb2+, and one Si4+ atom.