DOE OSTI2020
Cu6Pb2N2Se6O27 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing CuO5 square pyramids. There are a spread of Cu–O bond distances ranging from 1.81–2.64 Å. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing CuO5 square pyramids. There are a spread of Cu–O bond distances ranging from 1.81–2.61 Å. In the third Cu2+ site, Cu2+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share corners with two CuO5 square pyramids, an edgeedge with one CuO6 octahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.82–2.39 Å. In the fourth Cu2+ site, Cu2+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share corners with two CuO5 square pyramids, an edgeedge with one CuO6 octahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.82–2.39 Å. In the fifth Cu2+ site, Cu2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.95–2.54 Å. In the sixth Cu2+ site, Cu2+ is bonded to six O2- atoms to form distorted edge-sharing CuO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.94–2.34 Å. There are two inequivalent Pb2+ sites. In the first 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 2.35–3.09 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 2.39–2.94 Å. There are two inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.26 Å) and two longer (1.27 Å) N–O bond length. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.26 Å) and two longer (1.27 Å) N–O bond length. There are six inequivalent Se+4.67+ sites. In the first Se+4.67+ site, Se+4.67+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.73–1.76 Å. In the second Se+4.67+ site, Se+4.67+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.74 Å) and one longer (1.75 Å) Se–O bond length. In the third Se+4.67+ site, Se+4.67+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.70–1.82 Å. In the fourth Se+4.67+ site, Se+4.67+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.70–1.82 Å. In the fifth Se+4.67+ site, Se+4.67+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.68–1.79 Å. In the sixth Se+4.67+ site, Se+4.67+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.68–1.80 Å. There are twenty-seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to three Cu2+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Cu2+ atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one Pb2+ and one N5+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Pb2+ and one N5+ atom. In the fifth O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Cu2+ and one Se+4.67+ atom. In the sixth O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Cu2+ and one Se+4.67+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to one Cu2+ and one N5+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+ and one N5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Cu2+ and one N5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Cu2+ and one N5+ atom. In the seventeenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+ and one Se+4.67+ atom. In the eighteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+ and one Se+4.67+ atom. In the nineteenth O2- site, O2- is bonded in a distorted single-bond geometry to two Pb2+ and one Se+4.67+ atom. In the twentieth O2- site, O2- is bonded in a distorted single-bond geometry to two Pb2+ and one Se+4.67+ atom. In the twenty-first O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Cu2+ and one Se+4.67+ atom. In the twenty-second O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Cu2+ and one Se+4.67+ atom. In the twenty-third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Se+4.67+ atom. In the twenty-fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Se+4.67+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+, one Pb2+, and one Se+4.67+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Pb2+ atoms.