ELECTRONIC-STRUCTURE, ELECTRON-DENSITY, ELECTRIC-FIELD GRADIENT-TENSOR, MAGNETIC SUSCEPTIBILITY-TENSOR AND G-TENSOR OF K3FE(CN)6

Molecular orbital calculations are presented for the electronic structure of K3Fe(CN)6 based on clusters of formula K8Fe(CN)5+6, using a semi-empirical molecular orbital method including mixing of low-lying electronic configurations and spin-orbit coupling. The energy splittings obtained are in qualitative agreement with ligand field studies from several workers, excluding those of Merrithew and Modestino. While other authors interpret either Mössbauer data, or ESR results, or susceptibility values only, we obtain from the electron structure calculations charge densities at the iron nucleus, and electric field gradient, magnetic susceptibility and gyromagnetic tensors, which consistently interpret experimental Mössbauer-, EST- and magnetic anisotropy results. From the electronic structure calculations as well as from the reanalysis of experimental quadrupole line intensities (obtained by Oosterhuis and Lang) we derive that orthorhombic polytypism of K3Fe(CN)6 has to be considered for a consistent interpretation of the experimental data. The successful correlation between calculation and experiment in an energy range of about 300 K above the electronic groundstate is a measure for the adequacy of our electronic structure calculations in this low-energy range. © 1979.