Ab initio calculation of C-I bond dissociation of two alkyl iodide molecules

Employing the multiconfiguration self-consistent field method and the multiconfiguration quasi-degenerate perturbation method, the adiabatic potential energy curves and vertical excitation energies of alkyl iodides CF3I and C2H2F3I are calculated for the low-lying states, respectively. It is found that the low-lying excited states of the two molecules are repulsive, and the calculated dissociation energies for their ground states are 2.473 eV and 2.835 eV, respectively, in which the former one agrees well with the experimental results.