MECHGEN: computer aided generation and reduction of reaction mechanisms

The paper describes selection rules implemented in a software generating "possible reaction mechanism", i.e. a set of elementary reactions chosen from all stoichiometrically possible reactions. The novelty of the approach lies in the fact that the user has to define all species involved (reactants, intermediates, products), and the rules applied with user-set limits reduce the resulting mechanism to a reasonable set of possible elementary reactions. The computer code consists of five parts: (i) definition of species, and introducing its characteristics (structure and thermodynamic data); (ii) definition of the reacting system and generation of all stoichiometrically possible reactions; (iii) reduction of the mechanisms using complexity and thermodynamic constraints based on user-set limits; (iv) calculation of the resulting pathways (routes of the various atoms or groups of atoms transferred from one species to another); and (v) tools to help visualization of the process by finding those elementary processes which realize a given pathway. Reasonable flexibility is ensured for using selection rules based on various criteria with limits set by the user. The various pathways are shown (in a matrix form), which offers an overview of the entire process.