Many-electron calculations based upon a generalized Hubbard Hamiltonian for electronic states of the diamond vacancies were reported. The model did not use the configuration interaction method, and proper tetrahedral symmetry and spin properties of the defect were included in the Hamiltonian. Atomic orbital bases were introduced for the Hamiltonian calculation. Excited states of both neutral and negatively charged vacancies in diamond were calculated. The calculated values for the experimentally observed first dipole transition energies of the vacancies in diamond, GR1 and ND1 bands, were in good agreement with experiment. To obtain these results, a semi-empirical Hamiltonian parameter was used. The position of the low-lying 3T 1 state was found to be 260meV above the ground state, which was consistent with experiment. In addition to the energy spectrum, the model gave all the eigenfunctions of the vacancies, which had not been calculated before. This model had a high potential for further application to point defects in diamond and other semiconductors.

Generalized Hubbard Model for Many-Electron States of the Diamond Vacancies - a Non-CI Approach. M.H.Saani, M.A.Vesaghi, K.Esfarjani, A.Shafiekhani: Physica Status Solidi B, 2006, 243[6], 1269-75