Fifth Electronic Computational Chemistry Conference
ECCC-5
Email: |
Harold.Schranz@anu.edu.au |
| Address: |
Research School of Chemistry Australian National University Canberra, ACT, 0200 Australia |
Keywords: |
Monte Carlo, molecular dynamics, Transition State Theory, RRKM, microcanonical sampling |
Abstract:
In many theoretical and experimental studies of the unimolecular reaction of polyatomic systems it is quite common to employ harmonic approximations to the potential energy surface to calculate the statistical RRKM rate constant. However, this approximation may lead to significant errors, particularly for reactions at high energies, due to the lack of account of the anharmonicity present in a typical polyatomic potential surface. This deviation is demonstrated for a series of simple polyatomic models by comparing harmonic and anharmonic RRKM predictions to rate constants computed by molecular dynamics on the identical potential energy surfaces.