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 CF 3 I and C 2 H 2 F 3 I 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 2.473eV and 2.835eV, respectively, in which the former one agrees well with the experimental results.