Materials Data on Cu2H2Se2O7 by Materials Project
Cu2H2Se2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share a cornercorner with one CuO5 trigonal bipyramid, an edgeedge with one CuO6 octahedra, and an edgeedge with one CuO5 trigonal bipyramid. There are a spread of Cu–O bond distances ranging from 2.00–2.42 Å. In the second Cu2+ site, Cu2+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing CuO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 77°. There are a spread of Cu–O bond distances ranging from 1.95–2.65 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.70 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.75 Å) and one longer (1.77 Å) Se–O bond length. In the second 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 1.71–1.76 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Cu2+ and one Se4+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+ and one Se4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu2+, one H1+, and one Se4+ atom. In the fourth O2- site, O2- is bonded in a 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 one Cu2+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Cu2+ and one Se4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu2+ and one Se4+ atom.