Accurate DFT-D3 Calculations in a Small Basis Set.

Calculations of interaction energies of noncovalent interactions in small basis sets are affected by the basis set superposition error and dispersion-corrected DFT-D methods and are thus usually parametrized only for triple-ζ and larger basis sets. Nevertheless, some smaller basis sets could also perform well. Among many combinations tested, we obtained excellent results with the DZVP-DFT basis and newly parametrized D3 dispersion correction. The accuracy of interaction energies and geometries is close to significantly more expensive calculations.