DOI: 10.17188/1269582
title: Materials Data on NaBe2BO3F2 by Materials Project

description: NaBe2BO3F2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four F1- atoms. There are two shorter (2.32 Å) and two longer (2.44 Å) Na–F bond lengths. In the second Na1+ site, Na1+ is bonded in a distorted square co-planar geometry to four F1- atoms. There are two shorter (2.30 Å) and two longer (2.34 Å) Na–F bond lengths. In the third Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four F1- atoms. There are two shorter (2.34 Å) and two longer (2.41 Å) Na–F bond lengths. In the fourth Na1+ site, Na1+ is bonded to four F1- atoms to form distorted NaF4 trigonal pyramids that share corners with four BeO3F tetrahedra. There are two shorter (2.31 Å) and two longer (2.32 Å) Na–F bond lengths. There are four inequivalent Be2+ sites. In the first Be2+ site, Be2+ is bonded to three O2- and one F1- atom to form BeO3F tetrahedra that share corners with three BeO3F tetrahedra and a cornercorner with one NaF4 trigonal pyramid. There is two shorter (1.63 Å) and one longer (1.65 Å) Be–O bond length. The Be–F bond length is 1.54 Å. In the second Be2+ site, Be2+ is bonded to three O2- and one F1- atom to form corner-sharing BeO3F tetrahedra. There is two shorter (1.63 Å) and one longer (1.67 Å) Be–O bond length. The Be–F bond length is 1.54 Å. In the third Be2+ site, Be2+ is bonded to three O2- and one F1- atom to form BeO3F tetrahedra that share corners with three BeO3F tetrahedra and a cornercorner with one NaF4 trigonal pyramid. There are a spread of Be–O bond distances ranging from 1.65–1.67 Å. The Be–F bond length is 1.54 Å. In the fourth Be2+ site, Be2+ is bonded to three O2- and one F1- atom to form corner-sharing BeO3F tetrahedra. There is two shorter (1.64 Å) and one longer (1.65 Å) Be–O bond length. The Be–F bond length is 1.54 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.38 Å) and one longer (1.39 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.37 Å) and two longer (1.38 Å) B–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Be2+ and one B3+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two Be2+ and one B3+ atom. In the third O2- site, O2- is bonded in a trigonal planar geometry to two Be2+ and one B3+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two Be2+ and one B3+ atom. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to two Be2+ and one B3+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to two Be2+ and one B3+ atom. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to two Na1+ and one Be2+ atom. In the second F1- site, F1- is bonded in a 1-coordinate geometry to two Na1+ and one Be2+ atom. In the third F1- site, F1- is bonded in a 1-coordinate geometry to two Na1+ and one Be2+ atom. In the fourth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to two Na1+ and one Be2+ atom.