No abstract

In the absence of hydrophobic effects, the driving force for complexation between neutral host and guest molecules (e.g., cryptophane E and halomethanes) is a function of several factors. If size and form are suitable, as in the CHC13 complex 1, complexation is enthalpy driven, and stable supermolecules result (“van der Waals molecules”).

We identify peak and valley structures in the exact exchange-correlation potential of time-dependent density functional theory that are crucial for time-resolved electron scattering in a model one-dimensional system. These structures are completely missed by adiabatic approximations that, consequently, significantly underestimate the scattering probability. A recently proposed nonadiabatic approximation is shown to correctly capture the approach of the electron to the target when the initial Kohn-Sham state is chosen judiciously, and it is more accurate than standard adiabatic functionals but ultimately fails to accurately capture reflection. These results may explain the underestimation of scattering probabilities in some recent studies on molecules and surfaces.