Charge transfer in mixed valence solids. Part VII. Perturbation calculations of valence delocalization in iron(II,III) cyanides and silicates

Abstract

A method is described for calculating coupling integrals between donor and acceptor ions in class II mixed valence compounds. Metal–ligand–metal interactions are simulated by a perturbation model, which is then used to calculate valence delocalization coefficients from empirical and theoretical information On metal → ligand and ligand → metal charge transfer in the component single-valence complexes. The model is tested by applying it to Fe^II,III cyanides (Prussian Blue and its discrete molecular analogues) and silicates (e.g. biotite micas). Good agreement is found between observed and calculated intensities of the mixed valence charge transfer transitions.