Materials Data on Na4CrO3 by Materials Project

Abstract

Na4CrO3 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a trigonal planar geometry to three O2- atoms. There are one shorter (2.26 Å) and two longer (2.32 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.32–2.38 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.39–2.60 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form a mixture of distorted edge and corner-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.34–2.59 Å. Cr2+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Cr–O bond distances ranging from 1.93–2.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Cr2+ atom. In the second O2- site, O2- is bonded to five Na1+ and one Cr2+ atom to form corner-sharing ONa5Cr octahedra. The corner-sharing octahedral tilt angles are 62°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Cr2+ atom.