A refined study of the ionization energies of phosphorus and nitrogen trihalides

Abstract

The multiple-scattering Xα method has been used to study the orbital and ionization energies of a class of compounds possessing C_3ν symmetry. The study is mainly centred on the phosphorus and nitrogen trihalides, and the calculations are performed by using scattered waves around the central atom with and without the inclusion of d functions. Results obtained by our calculations reveal that the use of d functions around the central atom refines the ionization energies in comparison with experimental photoelectron studies. Moreover, our results seem to support our contention that the refinement in the case of the P-containing compounds is more significant than the similar refinement of the analogous N-containing compounds. This is attributed to the fact that the hypothetically empty 3d orbitals in phosphorus lend themselves to mixing with the valence-state orbitals of the molecules.