Classical trajectory studies of the molecular dissociation dynamics of formaldehyde: H2CO→H2+CO

Abstract

Classical trajectory calculations have been carried out to simulate the unimolecular decomposition of formaldehyde in the ground electronic state (S0). Global potential-energy surfaces were constructed using the empirical valence-bond (EVB) approach. Two sets of ab initio input were used to characterize two different EVB potential-energy surfaces, and trajectory calculations using one of these gives excellent agreement with experimental data for the product-state distributions of H2 and CO. The trajectory study of vector correlations with prompt dissociation of the parent molecule provides understanding of the dissociation dynamics in the molecular frame. From comparison with some of the experimental results and information from a few ab initio calculations, some improvements for the current potential surfaces are suggested.