Calculation of exchange interaction in exchange coupled dimers

In an effort to study the magnetostructural correlations in exchange coupled dimers, an attempt has been made to calculate the isotropic exchange using the molecular orbitals of unpaired electrons from extended Huckel theory methods. Calculation of the total isotropic exchange in a variety of Ni(III) dithiolene complexes is presented. Using the programs developed to obtain the antiferromagnetic and ferromagnetic contributions to the total exchange, various model systems have also been studied in order to get a good understanding of the variations of the two individual contributions with structural changes.