DOE OSTI2020
Cu7Se2(O4Cl3)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are eight inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four O2- and one Cl1- atom. There is three shorter (1.93 Å) and one longer (1.94 Å) Cu–O bond length. The Cu–Cl bond length is 2.93 Å. In the second Cu2+ site, Cu2+ is bonded to three O2- and three Cl1- atoms to form distorted CuCl3O3 octahedra that share corners with two equivalent CuCl2O3 trigonal bipyramids and edges with two equivalent CuCl3O2 square pyramids. There are a spread of Cu–O bond distances ranging from 1.92–2.01 Å. There are a spread of Cu–Cl bond distances ranging from 2.45–2.75 Å. In the third Cu2+ site, Cu2+ is bonded to two O2- and three Cl1- atoms to form distorted CuCl3O2 square pyramids that share a cornercorner with one CuCl4O2 octahedra, a cornercorner with one CuCl2O3 trigonal bipyramid, and edges with two equivalent CuCl3O3 octahedra. The corner-sharing octahedral tilt angles are 64°. There are one shorter (1.95 Å) and one longer (2.05 Å) Cu–O bond lengths. There are a spread of Cu–Cl bond distances ranging from 2.24–2.71 Å. In the fourth Cu2+ site, Cu2+ is bonded in a 4-coordinate geometry to two O2- and two Cl1- atoms. There is one shorter (1.97 Å) and one longer (1.99 Å) Cu–O bond length. There are one shorter (2.21 Å) and one longer (2.25 Å) Cu–Cl bond lengths. In the fifth Cu2+ site, Cu2+ is bonded in a 4-coordinate geometry to two O2- and four Cl1- atoms. There are one shorter (1.93 Å) and one longer (2.07 Å) Cu–O bond lengths. There are a spread of Cu–Cl bond distances ranging from 2.28–3.16 Å. In the sixth Cu2+ site, Cu2+ is bonded to four O2- and two equivalent Cl1- atoms to form distorted edge-sharing CuCl2O4 octahedra. There is two shorter (1.94 Å) and two longer (1.97 Å) Cu–O bond length. Both Cu–Cl bond lengths are 2.78 Å. In the seventh Cu2+ site, Cu2+ is bonded to three O2- and two Cl1- atoms to form distorted CuCl2O3 trigonal bipyramids that share corners with two equivalent CuCl3O3 octahedra, a cornercorner with one CuCl3O2 square pyramid, and an edgeedge with one CuCl2O4 octahedra. The corner-sharing octahedra tilt angles range from 38–65°. There are a spread of Cu–O bond distances ranging from 1.96–2.23 Å. There are one shorter (2.19 Å) and one longer (2.42 Å) Cu–Cl bond lengths. In the eighth Cu2+ site, Cu2+ is bonded to two equivalent O2- and four Cl1- atoms to form distorted corner-sharing CuCl4O2 octahedra. Both Cu–O bond lengths are 1.94 Å. There are two shorter (2.33 Å) and two longer (2.94 Å) Cu–Cl bond lengths. There are two inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.69–1.81 Å. In the second Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.72 Å) and two longer (1.76 Å) Se–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Cu2+ atoms to form corner-sharing OCu4 tetrahedra. In the second O2- site, O2- is bonded to four Cu2+ atoms to form corner-sharing OCu4 tetrahedra. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+ and one Se4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Se4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Se4+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Cu2+ and one Se4+ atom. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to two Cu2+ and one Se4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Se4+ atom. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted trigonal non-coplanar geometry to three Cu2+ atoms. In the second Cl1- site, Cl1- is bonded in a 1-coordinate geometry to three Cu2+ atoms. In the third Cl1- site, Cl1- is bonded in an L-shaped geometry to two Cu2+ atoms. In the fourth Cl1- site, Cl1- is bonded in a 1-coordinate geometry to four Cu2+ atoms. In the fifth Cl1- site, Cl1- is bonded in a 3-coordinate geometry to three Cu2+ atoms. In the sixth Cl1- site, Cl1- is bonded in a 1-coordinate geometry to three Cu2+ atoms.