Materials Data on Li2Cu3(Se2O7)2 by Materials Project
Li2Cu3(Se2O7)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent CuO5 square pyramids and corners with two equivalent SeO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.03–2.07 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share corners with two equivalent SeO4 tetrahedra and corners with three equivalent LiO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.96–2.41 Å. In the second Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.91–2.67 Å. There are two inequivalent Se5+ sites. In the first Se5+ site, Se5+ is bonded in a distorted T-shaped geometry to three O2- atoms. There is two shorter (1.73 Å) and one longer (1.80 Å) Se–O bond length. In the second Se5+ site, Se5+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with two equivalent CuO5 square pyramids and corners with two equivalent LiO4 tetrahedra. There are a spread of Se–O bond distances ranging from 1.66–1.71 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+ and one Se5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Cu2+ and one Se5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+, one Cu2+, and one Se5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Li1+ and one Se5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cu2+, and one Se5+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Cu2+, and one Se5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cu2+ and one Se5+ atom.