Density-Functional Theory with Dispersion-Correcting Potentials for Methane: Bridging the Efficiency and Accuracy Gap between High-Level Wave Function and Classical Molecular Mechanics Methods

Abstract

Large clusters of noncovalently bonded molecules can only be efficiently modeled by classical mechanics simulations. One prominent challenge associated with this approach is obtaining force-field parameters that accurately describe noncovalent interactions. High-level correlated wave function methods, such as CCSD(T), are capable of correctly predicting noncovalent interactions, and are widely used to produce reference data. However, high-level correlated methods are generally too computationally costly to generate the critical reference data required for good force-field parameter development. In this work we present an approach to generate Lennard-Jones force-field parameters to accurately account for noncovalent interactions. We propose the use of a computational step that is intermediate to CCSD(T) and classical molecular mechanics, that can bridge the accuracy and computational efficiency gap between them, and demonstrate the efficacy of our approach with methane clusters. On the basis of CCSD(T)-level binding energy data for a small set of methane clusters, we develop methane-specific, atom-centered, dispersion-correcting potentials (DCPs) for use with the PBE0 density-functional and 6-31+G(d,p) basis sets. We then use the PBE0-DCP approach to compute a detailed map of the interaction forces associated with the removal of a single methane molecule from a cluster of eight methane molecules and use this map to optimize the Lennard-Jones parameters for methane. The quality of the binding energies obtained by the Lennard-Jones parameters we obtained is assessed on a set of methane clusters containing from 2 to 40 molecules. Our Lennard-Jones parameters, used in combination with the intramolecular parameters of the CHARMM force field, are found to closely reproduce the results of our dispersion-corrected density-functional calculations. The approach outlined can be used to develop Lennard-Jones parameters for any kind of molecular system.

Unveiling the mechanism of selective gate-driven diffusion of CO2 over N2 in MFU-4 metal–organic framework

“…In order to try to stick as much as possible to previously existing force fields, we have made a thorough literature review of epsilon and sigma parameters for Cl and H, with the results shown in Fig. S6 and S7, † implying the use of the following force fields: Kamath et al, 23 UFF, 15 Dietz and Heinzinger, 24 Kovacs et al, 25 Lopes et al, 26 Harnes et al, 27 reaxFF, 28 Liu et al, 29 Bureekaew et al, 30 and Torres et al 31 Being the energetics of the flexibility of the small pore a central point which is directly related to the diffusivity of any adsorbate through MFU-4, a modification of UFF is mandatory to describe more correctly the flexibility of MFU-4, and this has been done in the present study. Using cluster-based quantum-chemistry DFT-D data, two steps have been followed in the parameterisation:…”

Inter-layer potential for hexagonal boron nitride

“…9,10 Recently, the technological potential of other layered materials, such as hexagonal boron nitride (h-BN) and its derivative structures, has been realized. h-BN substrates have been shown to enhance the performance of graphene based electronic devices 2,6,7,[11][12][13][14][15][16][17][18] and the heterojunction constructed from these two materials has been predicted to present robust superlubric behavior. 19 Furthermore, boron nitride nanotubes (BNNTs) have been shown to serve as a better hydrogen storage medium than CNTs.…”

“…25,27,30 Hence, carefully tailored force-fields have to be developed in order to obtain physically meaningful results. 16 An example for such an interlayer force-field is the registry-dependent potential developed by Kolmogorov and Crespi for graphitic systems. 31 This potential, which takes into account the anisotropic nature of the interlayer interactions, has been shown to provide an appropriate balance between accuracy and computational burden in MD simulations of double-walled carbon nanotubes and layered graphene structures.…”

Theoretical Study of Methane Storage in Cu24(m-BDC)24

“…An alternative starting geometry also considered was the lowest-energy structure from a heuristic method to locate the global minimum on the OPLS potential energy surface. 41,42 In all cases except for the (CH 4 ) 4 cluster, the lower-symmetry starting structure produced stronger binding energies ( 37 The Cu−Cu distances in the Cu 2 O 8 units are slight too short, probably due to the absence of coordinated DMF and H 2 O molecules in the calculated structure. However, the Cu−O and cross-ring Cu−Cu distances are predicted very well.…”