Generalized symmetry-adapted interpolation procedure for finding transition states in internal rotations
✍ Scribed by Cristian Cardenas-Lailhacar; Michael C. Zerner
- Book ID
- 102652895
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 601 KB
- Volume
- 75
- Category
- Article
- ISSN
- 0020-7608
No coin nor oath required. For personal study only.
✦ Synopsis
A constrained procedure is examined for internal rotations and generalized in terms of the symmetry of the system, initial conditions, and intuitive ideas such as Hammond's postulate and the Brønsted coefficient. We find that this symmetryadapted interpolation procedure can be used to describe potential energy surfaces with a discrepancy from point-by-point calculations much smaller than the currently used procedures. New relations in terms of a reduced number of independent calculations are given from which second derivatives are obtained. Terms representing the Brønsted condition are shown to appear naturally in the potential energy expression, showing the simplicity of the method as well as giving a more quantitative interpretation of the Hammond postulate. Surfaces are calculated for the internal rotation of the ethylene᎐sulfur dioxide complex, ethane, stilbene and the CO -HCN tetramer internal 2 Ž motion. The model requires only two input values at each minima or initial and final . structures , representing a substantial reduction in computational cost and has been able to predict the location of the transition state with very small error.