Automated Chemical Kinetic Modeling via Hybrid Reactive Molecular Dynamics and Quantum Chemistry Simulations

An automated scheme for obtaining
chemical kinetic models from
scratch using reactive molecular dynamics and quantum chemistry simulations
is presented. This methodology combines the phase space sampling of
reactive molecular dynamics with the thermochemistry and kinetics
prediction capabilities of quantum mechanics. This scheme provides
the NASA polynomial and modified Arrhenius equation parameters for
all species and reactions that are observed during the simulation
and supplies them in the ChemKin format. The ab initio level of theory
for predictions is easily exchangeable, and the presently used G3MP2
level of theory is found to reliably reproduce hydrogen and methane
oxidation thermochemistry and kinetics data. Chemical kinetic models
obtained with this approach are ready to use for, e.g., ignition delay
time simulations, as shown for hydrogen combustion. The presented
extension of the ChemTraYzer approach can be used as a basis for methodological
advancement of chemical kinetic modeling schemes and as a black-box
approach to generate chemical kinetic models.