Materials Data on H2W2O7 by Materials Project
H2W2O7 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. W6+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of W–O bond distances ranging from 2.01–2.18 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to two equivalent W6+ and one H1+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent W6+ atoms. In the third O2- site, O2- is bonded to four equivalent W6+ atoms to form distorted corner-sharing OW4 tetrahedra.