John Barker

Professor Emeritus, Climate and Space Sciences and Engineering



We publish computer codes for computational chemical reaction kinetics calculations. Our long-term aim (not yet achieved!) is to develop predictive tools that are as good as experiments. Toward that end, we use statistical rate theories to predict thermal rate constants for comparison with experimental data and for making predictions. An example is Miller’s very powerful Semi-Classical Transition State Theory, which we implemented by using a variant of the Wang-Landau algorithm. We also use our codes, which are based on Gillespie’s stochastic simulation algorithm, for solving the chemical/collisional master equation for complicated unimolecular reaction systems. These calculations are used for interpreting experiments, interpolating and extrapolating sparse experimental data, and for predicting chemical product yields and rates of reactions. Our work is mostly applied to non-equilibrium atmospheric and combustion chemistry.

Research Areas

Physics-Specific Methods