Materials Data on Na4Bi2O5 by Materials Project

Abstract

Na4Bi2O5 crystallizes in the orthorhombic Pnna space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form edge-sharing NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.25–2.45 Å. In the second Na1+ site, Na1+ is bonded in a 2-coordinate geometry to four O2- atoms. There are two shorter (2.39 Å) and two longer (2.73 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded in a bent 150 degrees geometry to two equivalent O2- atoms. Both Na–O bond lengths are 2.16 Å. Bi3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.08–2.55 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two equivalent Bi3+ atoms. In the second O2- site, O2- is bonded to three Na1+ and one Bi3+ atom to form ONa3Bi tetrahedra that share a cornercorner with one ONa3Bi tetrahedra, a cornercorner with one ONa2Bi2 trigonal pyramid, and an edgeedge with one ONa3Bi tetrahedra. In the third O2- site, O2- is bonded to two equivalent Na1+ and two equivalent Bi3+ atoms to form distorted ONa2Bi2 trigonal pyramids that share corners with two equivalent ONa3Bi tetrahedra and corners with two equivalent ONa2Bi2 trigonal pyramids.