Materials Data on VAs2Pb2O9 by Materials Project
VPb2As2O9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. V4+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent VO6 octahedra and corners with four AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 35°. There are a spread of V–O bond distances ranging from 1.71–2.15 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Pb–O bond distances ranging from 2.54–3.16 Å. In the second Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pb–O bond distances ranging from 2.57–2.99 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent VO6 octahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of As–O bond distances ranging from 1.70–1.75 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent VO6 octahedra. The corner-sharing octahedra tilt angles range from 39–46°. All As–O bond lengths are 1.73 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three Pb2+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Pb2+ and one As5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one V4+, one Pb2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent V4+ and one Pb2+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one V4+, two Pb2+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one V4+, one Pb2+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one V4+, two Pb2+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to three Pb2+ and one As5+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to three Pb2+ and one As5+ atom.