A Comparative Study of the Reaction Dynamics of a Model System Using Different Criteria in Parameterizing the Potential Energy Function
Abstract
A comparative study of the reaction dynamics of a modal system using a potential energy function that has been parameterized according to two different criteria is presented. The molecule studied is methylene nitramine CH2NNO2 and the reaction studied is the N-N bond scission reaction. A mathematical description of the potential energy surface for the system was developed and parameters for the individual terms in the model were fitted to data obtained from ab initio computations. The first model was fitted to th Cartesian second derivatives of the energy for frequencies for the molecule. Unimolecular decay curves for the N-N bond scission reaction were computed at six energies between 2.9384 and 4.1884 eV. Not only do the two models disagree in the computed reaction rates, but the rates predicted by Model 1 are first- order and time independent while those obtained with Model 2 indicate erratic and non statistical behavior. This study shows the sensitivity of dynamics calculations to quantitative differences in potential energy surfaces fitted to different aspects of electronic structure calculations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1991
- Accession Number
- ADA242586
Entities
People
- Betsy M. Rice
- Cary F. Chabalowski
- George F. Adams
- Michael J. Page
- Richard C. Mowrey
Organizations
- Ballistic Research Laboratory