Materials Data on Na2LiBe2F7 by Materials Project
Na2LiBe2F7 crystallizes in the tetragonal P-42_1m space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.38–2.70 Å. Li1+ is bonded to four equivalent F1- atoms to form LiF4 tetrahedra that share corners with four equivalent BeF4 tetrahedra. All Li–F bond lengths are 1.87 Å. Be2+ is bonded to four F1- atoms to form BeF4 tetrahedra that share a cornercorner with one BeF4 tetrahedra and corners with two equivalent LiF4 tetrahedra. There are a spread of Be–F bond distances ranging from 1.53–1.62 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Na1+, one Li1+, and one Be2+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two equivalent Be2+ atoms. In the third F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent Na1+ and one Be2+ atom.