Materials Data on BaNa4Cu3F12 by Materials Project

Abstract

Na4BaCu3F12 crystallizes in the cubic Ia-3 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six F1- atoms to form NaF6 octahedra that share corners with six equivalent CuF6 octahedra and faces with two BaF12 cuboctahedra. The corner-sharing octahedra tilt angles range from 31–33°. All Na–F bond lengths are 2.27 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Na–F bond distances ranging from 2.32–2.66 Å. In the third Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four F1- atoms. There are two shorter (2.28 Å) and two longer (2.34 Å) Na–F bond lengths. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve F1- atoms to form BaF12 cuboctahedra that share faces with two equivalent NaF6 octahedra and faces with six equivalent CuF6 octahedra. There are six shorter (2.79 Å) and six longer (2.87 Å) Ba–F bond lengths. In the second Ba2+ site, Ba2+ is bonded to twelve F1- atoms to form BaF12 cuboctahedra that share faces with two equivalent NaF6 octahedra and faces with six equivalent CuF6 octahedra. There are six shorter (2.79 Å) and six longer (2.90 Å) Ba–F bond lengths. Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with two equivalent NaF6 octahedra, corners with four equivalent CuF6 octahedra, and faces with two BaF12 cuboctahedra. The corner-sharing octahedra tilt angles range from 31–35°. There are a spread of Cu–F bond distances ranging from 1.94–2.29 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a 5-coordinate geometry to three Na1+, one Ba2+, and one Cu2+ atom. In the second F1- site, F1- is bonded in a 4-coordinate geometry to two Na1+, one Ba2+, and one Cu2+ atom. In the third F1- site, F1- is bonded in a 4-coordinate geometry to one Na1+, one Ba2+, and two equivalent Cu2+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to one Na1+, one Ba2+, and two equivalent Cu2+ atoms.