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An efficient 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 different molecules and was calibrated by fitting reference BSSE data points computed with the counterpoise method. It is verified that the proposed exponential decaying functional form of the model is valid. This work focuses on hydrogen-bonded liquids, i.e., methanol, and more specific 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. [ABSTRACT FROM AUTHOR]

This work aims at a critical assessmentof properties predictingor extracting information on the density and structure of liquids.State-of-the-art NVT and NpT molecular dynamics (MD) simulations havebeen performed on five liquids: methanol, chloroform, acetonitrile,tetrahydrofuran, and ethanol. These simulations allow the computationof properties based on first principles, including the equilibriumdensity and radial distribution functions (RDFs), characterizing theliquid structure. Refinements have been incorporated in the MD simulationsby taking into account basis set superposition errors (BSSE). An extendedBSSE model for an instantaneous evaluation of the BSSE correctionshas been proposed, and their impact on the liquid properties has beenassessed. If available, the theoretical RDFs have been compared withthe experimentally derived RDFs. For some liquids, significant discrepancieshave been observed, and a profound but critical investigation is presentedto unravel the origin of these deficiencies. This discussion is focusedon tetrahydrofuran where the experiment reveals some prominent peakscompletely missing in any MD simulation. Experiments providing informationon liquid structure consist mainly of neutron diffraction measurementsoffering total structure factors as the primary observables. The splittingof these factors in reciprocal space into intra- and intermolecularcontributions is extensively discussed, together with their sensitivityin reproducing correct RDFs in coordinate space. [ABSTRACT FROM AUTHOR]