Materials Data on Na3CrCl6 by Materials Project
Na3CrCl6 is Ilmenite-like structured and crystallizes in the trigonal P-31c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six equivalent Cl1- atoms to form distorted NaCl6 octahedra that share corners with twelve equivalent NaCl6 pentagonal pyramids and edges with three equivalent CrCl6 octahedra. All Na–Cl bond lengths are 2.83 Å. In the second Na1+ site, Na1+ is bonded to six equivalent Cl1- atoms to form distorted NaCl6 pentagonal pyramids that share corners with three equivalent CrCl6 octahedra, corners with six equivalent NaCl6 octahedra, edges with three equivalent NaCl6 pentagonal pyramids, and a faceface with one CrCl6 octahedra. The corner-sharing octahedra tilt angles range from 42–66°. There are three shorter (2.79 Å) and three longer (2.91 Å) Na–Cl bond lengths. Cr3+ is bonded to six equivalent Cl1- atoms to form CrCl6 octahedra that share corners with six equivalent NaCl6 pentagonal pyramids, edges with three equivalent NaCl6 octahedra, and faces with two equivalent NaCl6 pentagonal pyramids. All Cr–Cl bond lengths are 2.38 Å. Cl1- is bonded in a distorted see-saw-like geometry to three Na1+ and one Cr3+ atom.