DOE OSTI2020
FePb4As2(O2Cl)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Fe2+ is bonded in a distorted square co-planar geometry to four O2- and two equivalent Cl1- atoms. There is two shorter (1.83 Å) and two longer (1.91 Å) Fe–O bond length. Both Fe–Cl bond lengths are 2.65 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to four O2- and four Cl1- atoms. There are a spread of Pb–O bond distances ranging from 2.49–2.64 Å. There are a spread of Pb–Cl bond distances ranging from 3.01–3.32 Å. In the second Pb2+ site, Pb2+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Pb–O bond distances ranging from 2.35–2.54 Å. As5+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.80–1.82 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Pb2+ and one As5+ atom. In the second O2- site, O2- is bonded to three Pb2+ and one As5+ atom to form distorted edge-sharing OAsPb3 tetrahedra. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Fe2+ and one Pb2+ atom. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 3-coordinate geometry to three equivalent Pb2+ atoms. In the second Cl1- site, Cl1- is bonded in a 1-coordinate geometry to one Fe2+ and one Pb2+ atom.