The H + CO ⇌ HCO reaction studied by ab initio benchmark calculations.

Peters, Phillip S; Duflot, Denis; Wiesenfeld, Laurent; Toubin, Céline

Document type :

Article dans une revue scientifique

DOI :

10.1063/1.4826171

PMID :

24182032

Title :

The H + CO ⇌ HCO reaction studied by ab initio benchmark calculations.

Author(s) :

Peters, Phillip S [Auteur]
Institut de Planétologie et d'Astrophysique de Grenoble [IPAG ]
Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 [PhLAM]
Duflot, Denis [Auteur]
Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 [PhLAM]
Physico-Chimie Moléculaire Théorique [PCMT]
Wiesenfeld, Laurent [Auteur]
Institut de Planétologie et d'Astrophysique de Grenoble [IPAG ]
Toubin, Céline [Auteur]
Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 [PhLAM]

Journal title :

Journal of Chemical Physics

Pages :

164310

Publisher :

American Institute of Physics

Publication date :

2013-10-28

ISSN :

0021-9606

HAL domain(s) :

Chimie/Chimie théorique et/ou physique

English abstract : [en]

: The title reaction has been calculated using complete active space self-consistent field and internally contracted multi-reference configuration interaction, including Davidson correction, calculations. Dunning's correlation ...
Show more >: The title reaction has been calculated using complete active space self-consistent field and internally contracted multi-reference configuration interaction, including Davidson correction, calculations. Dunning's correlation consistent atomic basis sets, together with several complete basis set extrapolation schemes, were employed. Core-valence and scalar relativistic effects were also taken into account, as well as anharmonicity of the vibrational modes. Core-valence correlation appears to have a large impact on the calculated frequencies, spectroscopic constants, and on the energetics. In particular, the best estimate for the HCO (DCO) formation barrier height at 0 K, 4.54 ± 0.14 (4.43 ± 0.14) kcal mol(-1) is larger than previous theoretical works and well above the usually accepted value of 2.0 ± 0.4 kcal mol(-1), measured at room temperature. Inclusion of temperature and entropy at 298 K does not seem to be able to solve this discrepancy. The present theoretical barrier height is therefore the recommended value. The exo-ergicity of the HCO (DCO) dissociation reaction, predicted to be -13.36 ± 0.57 (-14.72 ± 0.57) kcal mol(-1), is slightly below the experimental value. Finally, all tested density functionals fail to reproduce accurately both the formation and dissociation barriers.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Collections :

Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM) - UMR 8523

Source :

Harvested from HAL

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