A new ab initio potential energy surface for the collisional excitation of HCN by para- and ortho-H{sub 2}

Journal Article · Sat Dec 14 04:00:00 EST 2013 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4833676· OSTI ID:22253865

Denis-Alpizar, Otoniel ^[1]; Kalugina, Yulia ^[2]; Stoecklin, Thierry ^[1]; Vera, Mario Hernández ^[2]; Lique, François ^[3]

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1. Université de Bordeaux, ISM, CNRS UMR 5255, 33405 Talence Cedex (France)
2. LOMC - UMR 6294, CNRS-Université du Havre, 25 rue Philippe Lebon, BP 540, 76058, Le Havre (France)
3. Departamento de Física, Universidad de Matanzas, Matanzas 40100 (Cuba)

We present a new four-dimensional potential energy surface for the collisional excitation of HCN by H{sub 2}. Ab initio calculations of the HCN–H{sub 2} van der Waals complex, considering both molecules as rigid rotors, were carried out at the explicitly correlated coupled cluster with single, double, and perturbative triple excitations [CCSD(T)-F12a] level of theory using an augmented correlation-consistent triple zeta (aVTZ) basis set. The equilibrium structure is linear HCN–H{sub 2} with the nitrogen pointing towards H{sub 2} at an intermolecular separation of 7.20 a{sub 0}. The corresponding well depth is −195.20 cm{sup −1}. A secondary minimum of −183.59 cm{sup −1} was found for a T-shape configuration with the H of HCN pointing to the center of mass of H{sub 2}. We also determine the rovibrational energy levels of the HCN–para-H{sub 2} and HCN–ortho-H{sub 2} complexes. The calculated dissociation energies for the para and ortho complexes are 37.79 cm{sup −1} and 60.26 cm{sup −1}, respectively. The calculated ro-vibrational transitions in the HCN–H{sub 2} complex are found to agree by more than 0.5% with the available experimental data, confirming the accuracy of the potential energy surface.

• OSTI ID: 22253865
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 22 Vol. 139; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACCURACY
DISSOCIATION ENERGY
ENERGY LEVELS
EXCITATION
HYDROCYANIC ACID
HYDROGEN
POTENTIAL ENERGY
SURFACES
VAN DER WAALS FORCES