Materials Data on RbMgCrF6 by Materials Project
RbMgCrF6 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Rb1+ is bonded to six F1- atoms to form RbF6 octahedra that share corners with six equivalent MgF6 octahedra and corners with six equivalent CrF6 octahedra. The corner-sharing octahedra tilt angles range from 68–69°. There are a spread of Rb–F bond distances ranging from 3.14–3.24 Å. Mg2+ is bonded to six F1- atoms to form MgF6 octahedra that share corners with two equivalent MgF6 octahedra, corners with four equivalent CrF6 octahedra, and corners with six equivalent RbF6 octahedra. The corner-sharing octahedra tilt angles range from 43–69°. There is two shorter (1.97 Å) and four longer (2.02 Å) Mg–F bond length. Cr3+ is bonded to six F1- atoms to form CrF6 octahedra that share corners with two equivalent CrF6 octahedra, corners with four equivalent MgF6 octahedra, and corners with six equivalent RbF6 octahedra. The corner-sharing octahedra tilt angles range from 42–69°. There is four shorter (1.93 Å) and two longer (1.97 Å) Cr–F bond length. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Rb1+ and two equivalent Cr3+ atoms. In the second F1- site, F1- is bonded in a 2-coordinate geometry to one Rb1+ and two equivalent Mg2+ atoms. In the third F1- site, F1- is bonded in a 2-coordinate geometry to one Rb1+, one Mg2+, and one Cr3+ atom.