Materials Data on ZnAs2Pb2O9 by Materials Project
ZnPb2As2O9 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Zn2+ is bonded to six O2- atoms to form ZnO6 octahedra that share corners with two equivalent PbO6 octahedra, corners with four AsO4 tetrahedra, and edges with two equivalent ZnO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Zn–O bond distances ranging from 1.88–2.39 Å. There are two inequivalent Pb3+ sites. In the first Pb3+ site, Pb3+ is bonded to six O2- atoms to form PbO6 octahedra that share corners with two equivalent ZnO6 octahedra and corners with six AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Pb–O bond distances ranging from 2.23–2.34 Å. In the second Pb3+ site, Pb3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Pb–O bond distances ranging from 2.21–2.62 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 ZnO6 octahedra and corners with three equivalent PbO6 octahedra. The corner-sharing octahedra tilt angles range from 62–67°. There are a spread of As–O bond distances ranging from 1.67–1.76 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent ZnO6 octahedra and corners with three equivalent PbO6 octahedra. The corner-sharing octahedra tilt angles range from 47–54°. There are a spread of As–O bond distances ranging from 1.71–1.75 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Pb3+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to one Pb3+ and one As5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Zn2+ and one Pb3+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Pb3+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Zn2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two Pb3+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Zn2+, one Pb3+, and one As5+ atom.