Structure of RbFeO2, refined from a reticular pseudomerohedrally twinned crystal with six domains

Abstract

RbFeO2, rubidium oxoferrate, crystallizes as an orthorhombic structure. The crystals under investigation were composed of six individuals representing reticular pseudomerohedral twins with a pseudocubic twin lattice of index 4 because of the approximate equations a(8)1/2 = b(2)1/2 = c. The compound is isostructural with KFeO2 (KGaO2 type of structure) and is composed of [FeO4/2]– corner-sharing tetrahedra, forming a three-dimensional cristobalite-like network, with Rb+ ions occupying its interstices.