An analytic function describing the H+C2H4?C2H5 potential energy surface

A b initio SCF calculations, using the unrestricted STO-3G and 4-31G approximations, were carried out to determine the minimum energy path for H-atom addition to ethylene, the angular width of the H-atom addition entrance channel, and the reaction path for H-atom migration between the carbon atoms. The accuracy of the calculations is discussed. Using spectroscopic, thermodynamic, and the ab initio information, an analytic function is derived for the H+C2H4? potential energy surface. The analytic function is highly flexible and can be adjusted to fit more accurate quantum mechanical results as they become available.