Modeling systems with π-π interactions using the Hartree-Fock method with an empirical dispersion correction.

The accuracy of the Hartree-Fock method with an empirical dispersion correction, HF-D3, to model interaction energies and locate constrained minimum geometries is tested against more conventional correlation methods, such as second-order perturbation theory and coupled cluster theory, and against the sophisticated effective fragment potential model. HF-D3 was applied to substituted-benzene dimers in both sandwich and T-shaped configurations and to DNA base pair complexes in both hydrogen bonded and stacked geometries. Overall, HF-D3 is found to be a plausible and cost efficient substitute for higher levels of electronic structure theory, such as MP2, in systems with π-π interactions.