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

Abstract

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.

Enhancing the catalytic activity of hydronium ions through constrained environments

“…27). The core electrons were represented by norm-conserving Goedecker–Teter–Hutter pseudo-potentials282930 and the valence electron wave function was expanded in a double-zeta basis set with polarization functions31 along with an auxiliary plane wave basis set with an energy cutoff of 360 eV. In all calculations we used the generalized gradient approximation exchange-correlation functional of Perdew, Burke and Enzerhof32.…”

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“…The same computational settings are used as in ref apart from some convergence criteria. All simulations are performed with the CP2K code .…”

“…Molecular dynamics (MD) simulations offer the appropriate theoretical tools to compute RDFs directly (Figure ). They can be performed with force fields ,,,, or based on density functional theory. ,, MD modeling has proven to be very effective in guiding assignments of peaks in these empirical RDFs. In this work we will compute theoretical (partial) RDFs and their counterparts, the (partial) SFs, which are connected by a Fourier transform.…”

“…When the intermolecular distance decreases, they may use each other’s basis, causing an artificial strengthening of the intermolecular interactions and artificial shortening of intermolecular distances due to the overlap of basis functions. In ref , a systematic correction of the BSSE with an exponentially decaying parametrized pairwise classical force-field energy term has been proposed by the authors that can be added in subsequent MD simulations. The model was applied to methanol using MD in a canonical ensemble (NVT) with the BLYP-D functional.…”

“…An RDF is directly related to the density of the molecular system, so it is vital that the density in MD simulations is properly reproduced. In ref , the NVT ensemble was considered.…”