Materials Data on Na2La4O7 by Materials Project

Abstract

Na2La4O7 crystallizes in the trigonal P-31m space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Na–O bond lengths are 3.20 Å. There are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded to four O2- atoms to form LaO4 trigonal pyramids that share corners with six equivalent LaO6 octahedra and a cornercorner with one LaO4 trigonal pyramid. The corner-sharing octahedral tilt angles are 64°. There are one shorter (2.11 Å) and three longer (2.34 Å) La–O bond lengths. In the second La3+ site, La3+ is bonded to six equivalent O2- atoms to form LaO6 octahedra that share corners with six equivalent LaO4 trigonal pyramids and edges with three equivalent LaO6 octahedra. All La–O bond lengths are 2.44 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na1+ and three La3+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent La3+ atoms.