Materials Data on Na2Ta2O5 by Materials Project
Na2Ta2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. Na1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Na–O bond distances ranging from 2.59–3.07 Å. There are two inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Ta–O bond distances ranging from 1.99–2.02 Å. In the second Ta4+ site, Ta4+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There is three shorter (1.95 Å) and one longer (1.96 Å) Ta–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Na1+ and two equivalent Ta4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Na1+ and two Ta4+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Na1+ and two equivalent Ta4+ atoms.