Coupling Between Rotational and Vibrational Degrees of Freedom in Field-induced Dynamics of van der Waals Dimers

In many molecules, the scales of the rotational energies and vibrational energies are vastly different. This justifies treating the two degrees of freedom separately. However, in the case of molecules that are bound weakly by van der Waals forces, the vibrational energy scale may not be much larger than the rotational energy scale. Motivated by this, we theoretically investigate the coupling between the rotational and vibrational degrees of freedom within the context of pump-probe dynamics (i.e., for short intense laser pulses). Using the neon dimer as an example, we apply a Gaussian laser pulse and monitor how the inclusion of the radial degree of freedom impacts the dynamics of the angular or rotational degrees of freedom. Results for the wave packet dynamics are also shown for non-Gaussian pulse shapes.