Full-dimensional automated potential energy surface development and dynamics for the OH + C 2 H 6 reaction

We develop a full-dimensional analytical potential energy surface (PES) for the OH + C 2 H 6 reaction using the Robosurfer program system, which automatically (1) selects geometries from quasi-classical trajectories, (2) performs ab initio computations using a coupled-cluster singles, doubles, and p...

Teljes leírás

Elmentve itt :
Bibliográfiai részletek
Szerzők: Gruber Balázs
Tajti Viktor
Czakó Gábor
Dokumentumtípus: Cikk
Megjelent: 2022
Sorozat:JOURNAL OF CHEMICAL PHYSICS 157 No. 7
Tárgyszavak:
doi:10.1063/5.0104889

mtmt:33119360
Online Access:http://publicatio.bibl.u-szeged.hu/25725
Leíró adatok
Tartalmi kivonat:We develop a full-dimensional analytical potential energy surface (PES) for the OH + C 2 H 6 reaction using the Robosurfer program system, which automatically (1) selects geometries from quasi-classical trajectories, (2) performs ab initio computations using a coupled-cluster singles, doubles, and perturbative triples-F12/triple-zeta-quality composite method, (3) fits the energies utilizing the permutationally invariant monomial symmetrization approach, and (4) iteratively improves the PES via steps (1)–(3). Quasi-classical trajectory simulations on the new PES reveal that hydrogen abstraction leading to H 2 O + C 2 H 5 dominates in the collision energy range of 10–50 kcal/mol. The abstraction cross sections increase and the dominant mechanism shifts from rebound (small impact parameters and backward scattering) to stripping (larger impact parameters and forward scattering) with increasing collision energy as opacity functions and scattering angle distributions indicate. The abstraction reaction clearly favors side-on OH attack over O-side and the least-preferred H-side approach, whereas C 2 H 6 behaves like a spherical object with only slight C–C-perpendicular side-on preference. The collision energy efficiently flows into the relative translation of the products, whereas product internal energy distributions show only little collision energy dependence. H 2 O/C 2 H 5 vibrational distributions slightly/significantly violate zero-point energy and are nearly independent of collision energy, whereas the rotational distributions clearly blue-shift as the collision energy increases.
Terjedelem/Fizikai jellemzők:9
ISSN:0021-9606