Materials Data on Mg5Pb(SO4)6 by Materials Project

Abstract

PbMg5(SO4)6 crystallizes in the trigonal P-3 space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent PbO12 cuboctahedra, corners with six SO4 tetrahedra, and a faceface with one MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.21 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share a cornercorner with one PbO12 cuboctahedra, corners with six SO4 tetrahedra, and a faceface with one MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.24 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six SO4 tetrahedra and faces with two equivalent PbO12 cuboctahedra. There are three shorter (2.14 Å) and three longer (2.15 Å) Mg–O bond lengths. In the fourth Mg2+ site, Mg2+ is bonded to six equivalent O2- atoms to form distorted MgO6 octahedra that share corners with six equivalent SO4 tetrahedra and faces with two equivalent PbO12 cuboctahedra. All Mg–O bond lengths are 2.11 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to twelve O2- atoms to form PbO12 cuboctahedra that share corners with six equivalent MgO6 octahedra, edges with six SO4 tetrahedra, and faces with two equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 45–49°. There are a spread of Pb–O bond distances ranging from 2.66–3.08 Å. In the second Pb2+ site, Pb2+ is bonded to twelve O2- atoms to form PbO12 cuboctahedra that share corners with six equivalent MgO6 octahedra, edges with six equivalent SO4 tetrahedra, and faces with two equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are six shorter (2.72 Å) and six longer (3.02 Å) Pb–O bond lengths. There are three inequivalent S6+ sites. In the first S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with five MgO6 octahedra and an edgeedge with one PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 16–54°. There are a spread of S–O bond distances ranging from 1.46–1.50 Å. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with five MgO6 octahedra and an edgeedge with one PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 22–54°. There are a spread of S–O bond distances ranging from 1.46–1.50 Å. In the third S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with five MgO6 octahedra and an edgeedge with one PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 16–52°. There are a spread of S–O bond distances ranging from 1.46–1.50 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Pb2+, and one S6+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mg2+, one Pb2+, and one S6+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mg2+, one Pb2+, and one S6+ atom. In the fourth O2- site, O2- is bonded in a linear geometry to one Mg2+ and one S6+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Pb2+, and one S6+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+ and one S6+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+ and one S6+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mg2+, one Pb2+, and one S6+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mg2+ and one S6+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Pb2+, and one S6+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+ and one S6+ atom. In the twelfth O2- site, O2- is bonded in a linear geometry to one Mg2+ and one S6+ atom.