Dick, Bernhard and Haas, Yehuda and Zilberg, Shmuel (2008) Locating conical intersections relevant to photochemical reactions. CHEMICAL PHYSICS, 347 (1-3). pp. 65-77. ISSN 0301-0104, 1873-4421
Full text not available from this repository. (Request a copy)Abstract
A new computerized method for locating conical intersections of interest in photochemistry is presented. The search is based on the Longuet-Higgins phase change theorem (Berry phase) which provides the subspace required for the initial search. The subspace is approximated as a plane containing three stable structures lying on a Longuet-Higgins loop. The search is conducted for a minimum of Delta E, the energy difference between two electronic states. It is started using up to three points within the circle defined by the three structures; symmetry, if relevant, is helpful but not essential. Since a two-dimensional subspace of the large 3N - 6 space is used, the search that uses either Cartesian or internal coordinates is efficient and yields a degeneracy after a few iterations. Given that not all degrees of freedom are included in the search, usually a high lying part of the conical intersection is initially located. The system is subsequently optimized along all coordinates keeping Delta E as close to zero as desired. The method is demonstrated for the symmetric H-3 system and also for the butadiene-cyclobutene-bicyclobutane system in which the three stable structures are not equivalent. The method is general and can be extended to any photochemical system. (c) 2007 Elsevier B.V. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | POTENTIAL-ENERGY SURFACES; STATE REACTION PATHS; S-TRANS-BUTADIENE; POLYATOMIC-MOLECULES; PHASE-CHANGE; MC-SCF; GENERAL-METHOD; CIS BUTADIENE; H-3 SYSTEM; DYNAMICS; conical intersections; Longuet-Higgins loop; butadiene; cyclobutene; bicyclobutane |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Bernhard Dick |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Nov 2020 13:34 |
| Last Modified: | 02 Nov 2020 13:34 |
| URI: | https://pred.uni-regensburg.de/id/eprint/30884 |
Actions (login required)
 |
View Item |
