Materials Data on U3W2O17F2 by Materials Project
U3W2O17F2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent U sites. In the first U site, U is bonded to six O and one F atom to form distorted UO6F pentagonal bipyramids that share corners with three equivalent WO6 octahedra, a cornercorner with one UO6F pentagonal bipyramid, an edgeedge with one WO6 octahedra, and an edgeedge with one UO6F pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 31–40°. There are a spread of U–O bond distances ranging from 1.79–2.47 Å. The U–F bond length is 2.27 Å. In the second U site, U is bonded to five O and two equivalent F atoms to form distorted UO5F2 pentagonal bipyramids that share corners with two equivalent WO6 octahedra and an edgeedge with one UO5F2 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 20°. There are a spread of U–O bond distances ranging from 1.80–2.43 Å. Both U–F bond lengths are 2.33 Å. W is bonded to six O atoms to form distorted WO6 octahedra that share corners with four UO6F pentagonal bipyramids, an edgeedge with one WO6 octahedra, and an edgeedge with one UO6F pentagonal bipyramid. There are a spread of W–O bond distances ranging from 1.81–2.12 Å. There are ten inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one W atom. In the second O site, O is bonded in a single-bond geometry to one U atom. In the third O site, O is bonded in a bent 150 degrees geometry to one U and one W atom. In the fourth O site, O is bonded in a single-bond geometry to one U atom. In the fifth O site, O is bonded in a single-bond geometry to one U atom. In the sixth O site, O is bonded in a single-bond geometry to one U atom. In the seventh O site, O is bonded in a 3-coordinate geometry to two equivalent U and one W atom. In the eighth O site, O is bonded in a single-bond geometry to one U atom. In the ninth O site, O is bonded in a bent 150 degrees geometry to one U and one W atom. In the tenth O site, O is bonded in a distorted trigonal non-coplanar geometry to one U and two equivalent W atoms. There are two inequivalent F sites. In the first F site, F is bonded in a linear geometry to two equivalent U atoms. In the second F site, F is bonded in a bent 120 degrees geometry to two equivalent U atoms.