Optical Transitions at the Neutral and Charged Vacancies in Diamond

We used the exact eigenvectors of the generalized Hubbard Hamiltonian solution to predict the transition intensities of the well known $GR1$ and $ND1$ transitions at the neutral and charged vacancies in diamond. In addition to using exact eigenvectors, the method of the calculation is more precise than already reported calculations. The quantitative results can exlain recent experimental data very good.