Materials Data on SmAl3(PbO4)2 by Materials Project

Abstract

SmAl3(PbO4)2 is Esseneite-like structured and crystallizes in the cubic Pn-3m space group. The structure is three-dimensional. Sm3+ is bonded to eight O2- atoms to form SmO8 hexagonal bipyramids that share edges with six equivalent AlO4 tetrahedra. There are two shorter (2.32 Å) and six longer (2.59 Å) Sm–O bond lengths. Al3+ is bonded to four equivalent O2- atoms to form AlO4 tetrahedra that share corners with four equivalent AlO4 tetrahedra and edges with two equivalent SmO8 hexagonal bipyramids. All Al–O bond lengths are 1.76 Å. Pb2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.36 Å) and three longer (3.18 Å) Pb–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sm3+, two equivalent Al3+, and one Pb2+ atom. In the second O2- site, O2- is bonded to one Sm3+ and three equivalent Pb2+ atoms to form a mixture of distorted corner and edge-sharing OSmPb3 tetrahedra.