Application of the Stabilized Koopmans' Theorem to the Temporary Anion States of Chlorosilanes in Long-Range Corrected Density Functional Theory

The stabilized Koopmans' theorem (SKT) is very successful in predicting relative vertical electron attachment energies in the Hartree-Fock theory. It is mainly accomplished by systematically scaling the most diffuse functions in the basis set. Recently, the SKT has been extended to the temporary anion states (TASs) of polyatomic molecules in the long-range corrected density functional theory. In this paper, this method will be further applied to chlorosilanes for their importance in the chemical processes of the semiconductor industry. Their resonance energies and lifetimes are determined by computing the density of resonance states via SKT. The detailed characteristics of resonance orbitals are then analyzed. It turns out that the lowest unfilled orbitals of chlorosilanes are essentially sigma*(Si-Cl) in character. Moreover, several TASs with strong Si/Cl "d" character have been identified. These results, definitely, will help us in understanding the peculiar bonding and chemical properties of chlorosilanes.