Materials Data on Li2W2O7 by Materials Project
Li2W2O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.14 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form distorted LiO6 octahedra that share corners with two equivalent WO6 octahedra, an edgeedge with one LiO6 octahedra, and an edgeedge with one WO6 octahedra. The corner-sharing octahedra tilt angles range from 23–27°. There are a spread of Li–O bond distances ranging from 1.99–2.44 Å. There are two inequivalent W6+ sites. In the first W6+ site, W6+ is bonded to six O2- atoms to form distorted WO6 octahedra that share corners with two equivalent LiO6 octahedra, an edgeedge with one LiO6 octahedra, and an edgeedge with one WO6 octahedra. The corner-sharing octahedra tilt angles range from 23–27°. There are a spread of W–O bond distances ranging from 1.79–2.14 Å. In the second W6+ site, W6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of W–O bond distances ranging from 1.79–2.26 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+ and two W6+ atoms. In the second O2- site, O2- is bonded in a T-shaped geometry to two Li1+ and one W6+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+ and two W6+ atoms. In the fourth O2- site, O2- is bonded in a T-shaped geometry to two Li1+ and one W6+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three W6+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Li1+ and two W6+ atoms to form distorted edge-sharing OLi2W2 trigonal pyramids. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Li1+ and one W6+ atom.