New global potential energy surfaces of the ground 3A' and 3Aâ³ states of the O(3P) + H2 system.
J Chem Phys
; 151(9): 094307, 2019 Sep 07.
Article
in En
| MEDLINE
| ID: mdl-31492055
ABSTRACT
This paper presents two new adiabatic, global potential energy surfaces (PESs) for the two lowest 3A' and 3Aâ³ electronic states of the O(3P) + H2 system. For each of these states, ab initio electronic energies were calculated for more than 5000 geometries using internally contracted multireference configuration interaction methods. The calculated points were then fitted using the ansatz by Aguado et al. [Comput. Phys. Commun. 108, 259 (1998)] leading to very accurate analytical potentials well adapted to perform reaction dynamics studies. Overall, the topographies of both PESs are in good agreement with the benchmark potentials of Rogers et al. [J. Phys. Chem. A 104, 2308 (2000)], but those presented in this work reproduce better the height and degeneracy of the two states at the saddle point. Moreover, the long range potential in the entrance channel does not require any cutoff. These features make the new PESs particularly suitable for a comparison of the dynamics on each of them. The new set of PESs was then used to perform quantum mechanics and quasiclassical trajectory calculations to determine differential and integral cross sections, which are compared to the experimental measurements by Garton et al. [J. Chem. Phys. 118, 1585 (2003)].
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Chem Phys
Year:
2019
Document type:
Article
Affiliation country:
Spain