Theoretical Study on the Proton Affinity of Small Molecules Using Gaussian Basis Sets in the LCAO–MO–SCF Framework

The proton affinities of certain small molecules have been calculated as an energy difference between the parent molecule and the protonated species. Various size Gaussian basis sets were used to see how the calculated proton affinities approximate the experimental values as the wavefunctions approached the Hartree–Fock limit. The correlation between experimental and calculated proton affinities was excellent with the extensive basis sets.