Structure and thermal expansion of the distorted Prussian blue analogue RbCuCo(CN)6

Abstract

The structure and thermal expansion of the Prussian blue analogue RbCuCo(CN)₆ has been determined via neutron and X-ray powder diffraction. The system crystallises in Cccm and harbours three coexisting distortions relative to the parent Fmm structure, which leads to anisotropic thermal expansion with a near-zero component in one direction. The difficulties associated with determining octahedral tilt systems in Prussian blue analogues and related double molecular perovskites are discussed.