Formation Enthalpies Derived from Pairwise Interactions: A Step toward More Transferable Reactive Potentials for Organic Compounds

A new approach to the development and parametrization of reactive potentials for organic compounds is put forward. As a byproduct of preliminary efforts in this direction, the performance of a simple representation of the energy of equilibrium structures in term of pairwise atom–atom and bond–bond contributions is investigated. For now, each contribution is assumed constant, given the multiplicity of covalent bonds, rather than computed on-the-fly from geometries and bond orders. In spite of this rough approximation, the approach performs remarkably well by comparison with semiempirical quantum chemical methods. Nevertheless, further refinement proves necessary for some unstable species involved in chemical reactions. As it stands, the present model appears as a promising basis in view of less empirical and more versatile alternatives to group contribution methods for the fast prediction of heats of formation, although much work remains to be done to demonstrate its value as a starting point toward better reactive potentials.