Embedded cluster approach: Application to complex defects

A hybrid Quantum Mechanics/Classical Mechanics method implementing an embed ded cluster approach has been applied to model the ferricyanide impurity in the NaCl crystal. Binding energies for the nine symmetry unrelated configu rations of the two compensating cation vacancies are calculated and assignm ent of the most stable configurations compared with experimental data. The electronic structure of the complex is calculated using the B3LYP hybrid Fu nctional. Absorption spectra are calculated using the CIS method and compar ed with experiment. Electron affinities of several charge uncompensated com plexes are calculated.