Copyright © 2012 Robert J. Hinde. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We examine the interaction between an open-shell chlorine atom and a para-H₂ molecule in the region of configuration space that corresponds to a weakly bound Cl–para-H₂ van der Waals dimer. By constructing and diagonalizing the Hamiltonian matrix that represents the coupled Cl atom electronic and H₂ rotational degrees of freedom, we obtain one-dimensional energy curves for the Cl–para-H₂ system in this region of configuration space. We find that the dimer exhibits fairly strong electronic-rotational coupling when the Cl–H₂ distance R is close to ; however, this coupling does not modify substantially the positions and depths of the van der Waals wells in the dimer’s curves. An approximation in which the para-H₂ fragment is treated in the strict limit thus appears to yield an accurate representation of those states of the weakly bound Cl–para-H₂ dimer that correlate with H₂ in the limit.