Materials Data on Al2Si2PbO8 by Materials Project

Abstract

PbAl2Si2O8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.78 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There is three shorter (1.76 Å) and one longer (1.77 Å) Al–O bond length. Pb2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pb–O bond distances ranging from 2.44–3.13 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+, one Pb2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+, one Pb2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Pb2+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Al3+ and two equivalent Pb2+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to one Al3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Al3+, one Pb2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Al3+, one Pb2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Al3+, one Pb2+, and one Si4+ atom.