Description of the Chemical Reaction Path in the HCO Molecule: A Combined Configuration Interaction and Tight-Binding Approach

It is demonstrated that the reaction path for a polyatomic molecule (applied to the HCO molecule) is easily calculated via ab-initio configuration interaction (CI) total energies. This Hamiltonian not only reproduces the CI calculations accurately and efficiently, but also effectively corrects any CI energies happening to erroneously converge to excited states.