Collect. Czech. Chem. Commun. 2004, 69, 1-12
https://doi.org/10.1135/cccc20040001

On the Structure and Physical Origin of the Weak Interaction Between H and CO

Vladimír Lukeša, Viliam Laurinca,*, Michal Ilčina and Stanislav Biskupičb

a Department of Chemical Physics, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovak Republic
b Department of Physical Chemistry, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovak Republic

Abstract

The adiabatic potential energy surface of the H-CO complex in the van der Waals region, described by Jacobi coordinates (r = 1.128 Å, R, Θ), was investigated using the supermolecular coupled-clusters CCSD(T) method. Our calculations indicate a minimum for bent arrangements. It was found on the carbon side of CO molecule at R = 3.6 Å (Θ = 76°) with a well depth of De = -156.5 μEh. The saddle points are localised at linear conformations for R = 4.37 Å (Θ = 0°) and R = 3.91 Å (Θ = 180°). The physical origin of the studied interaction was analysed by the intermolecular perturbation theory based on the single-determinant unrestricted Hartree-Fock wave function. The separation of the interaction energies shows that the locations of the predicted stable bent structure is primarily determined by delicate balance between the repulsive Heitler-London and attractive dispersion and induction energy components.

Keywords: Interaction energy; Potential energy surface; H-CO; van der Waals complex; Intermolecular perturbation theory; Coupled clusters; CCSD(T) method; Ab initio calculation.

References: 43 live references.