Materials Data on FeAs2PbO8 by Materials Project
FePbAs2O8 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six AsO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.97–2.12 Å. Pb4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Pb–O bond distances ranging from 2.36–2.54 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 three equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of As–O bond distances ranging from 1.70–1.76 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 41–57°. There are a spread of As–O bond distances ranging from 1.71–1.75 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe2+ and one As5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Fe2+, one Pb4+, and one As5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Fe2+, one Pb4+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Pb4+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Fe2+, one Pb4+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Pb4+ and one As5+ atom.