Materials Data on Na3HfF7 by Materials Project
Na3HfF7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Na–F bond distances ranging from 2.35–2.55 Å. In the second Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five F1- atoms. There are a spread of Na–F bond distances ranging from 2.27–2.36 Å. Hf4+ is bonded in a distorted pentagonal bipyramidal geometry to seven F1- atoms. There are a spread of Hf–F bond distances ranging from 2.05–2.09 Å. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one Hf4+ atom. In the second F1- site, F1- is bonded to three Na1+ and one Hf4+ atom to form a mixture of edge and corner-sharing FNa3Hf tetrahedra. In the third F1- site, F1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one Hf4+ atom. In the fourth F1- site, F1- is bonded to three Na1+ and one Hf4+ atom to form a mixture of edge and corner-sharing FNa3Hf tetrahedra. In the fifth F1- site, F1- is bonded to three Na1+ and one Hf4+ atom to form a mixture of edge and corner-sharing FNa3Hf tetrahedra.