Analysis of the basis set superposition error in molecular dynamics of hydrogen-bonded liquids: application to methanol

M. Van Houteghem, T. Verstraelen, A. Ghysels, L. Vanduyfhuys, M. Waroquier, V. Van Speybroeck
Journal of Chemical Physics
137 (10), 104506


An ecient protocol is presented to compensate for the basis set superposition error (BSSE) in DFT molecular dynamics (MD) simulations using localized Gaussian basis sets. We propose a classical correction term that can be added a posteriori to account for BSSE. It is tested to what extension this term will improve radial distribution functions (RDFs). The proposed term is pairwise between certain atoms in dierent molecules and was calibrated by tting reference BSSE data points computed with the counterpoise method. It is veried that the proposed exponential decaying functional form of the model is valid. This work focuses on hydrogen-bonded liquids, i.e. methanol, and more specic on the intermolecular hydrogen bond, but in principle the method is generally applicable on any type of interaction where BSSE is significant. We evaluated the relative importance of the Grimme-dispersion versus BSSE and found that they are of the same order of magnitude, but with an opposite sign. Upon introduction of the correction, the relevant RDFs, obtained from MD, have amplitudes equal to experiment.

Open Access version available at UGent repository