材料期刊网

The EPR g-shift Delta g (approximate to g-ge) of the metal-cyanide cluster [Cr(CN)(6)](3-) is calculated by high-order perturbation formulas based on both the crystal-field (CF) and charge-transfer (CT) mechanisms (the latter is often neglected in the crystal-field theory). The result agrees with the experimental value. The sign of the g-shift Delta g(CT) due to the contribution of the CT mechanism is opposite to that of Delta g(CF) due to the contribution of the CF mechanism, and the absolute value of Delta 8CT is about 34% of that of Delta g(CF). It appears that for transition metal ions in a strong covalent cluster, a reasonable theoretical explanation of the g-shift should take both the CF and CT mechanism into account.