Extension of the B3LYP–dispersion-correcting potential approach to the accurate treatment of both inter- and intra-molecular interactions

Abstract

We recently showed that dispersion-correcting potentials (DCPs), atom-centered Gaussian-type functions developed for use with B3LYP (J. Phys. Chem. Lett. 2012, 3, 1738-1744 greatly improved the ability of the underlying functional to predict non-covalent interactions. However, the application of B3LYP-DCP for the β-scission of the cumyloxyl radical led a calculated barrier height that was over-estimated by ca. 8 kcal/mol. We show in the present work that the source of this error arises from the previously developed carbon atom DCPs, which erroneously alters the electron density in the C-C covalent-bonding region. In this work, we present a new C-DCP with a form that was expected to influence the electron density farther from the nucleus. Tests of the new C-DCP, with previously published H-, N-and O-DCPs, with B3LYP-DCP/6-31+G(2d,2p) on the S66, S22B, HSG-A, and HC12 databases of non-covalently interacting dimers showed that it is one of the most accurate methods available for treating intermolecular interactions, giving mean absolute errors (MAEs) of 0.19, 0.27, 0.16, and 0.18 kcal/mol, respectively. Additional testing on the S12L database of complexation systems gave an MAE of 2.6 kcal/mol, showing that the B3LYP-DCP/6-31+G(2d,2p) approach is one of the best-performing and feasible methods for treating large systems dominated by non-covalent interactions. Finally, we showed that C-C making/breaking chemistry is well-predicted using the newly developed DCPs. In addition to predicting a barrier height for the β-scission of the cumyloxyl radical that is within 1.7 kcal/mol of the high-level value, application of B3LYP-DCP/6-31+G(2d,2p) to 10 databases that include reaction barrier heights and energies, isomerization energies and relative conformation energies gives performance that is amongst the best of all available dispersion-corrected density-functional theory approaches.

Dispersion-correcting potentials can significantly improve the bond dissociation enthalpies and noncovalent binding energies predicted by density-functional theory

“…22 (0.19 kcal/mol using the revised C DCPs as described in Ref. 38). We also evaluated the performance of the LC-ωPBE-D3/6-31+G(2d,2p) and find that the overall MAE for the S66 set is 0.39 kcal/mol, which is the result of nearly uniform over-binding in the dimers.…”

“…38 Motivated by this unexplored feature of DCPs and by the notion that range-separated functionals might offer more accurate modeling for a broader spectrum of complexes and chemical properties, we present in this work DCPs for the H, C, N, and O atoms developed for use with the LC-ωPBE functional. 39,40 II.…”

Small Atomic Orbital Basis Set First‐Principles Quantum Chemical Methods for Large Molecular and Periodic Systems: A Critical Analysis of Error Sources

“…One possibility to include London dispersion effects in DFT calculations is to correct the long‐range interaction by atom‐centered potentials, so called dispersion‐correcting potentials (DCPs) . Though the correct physical terms leading to the London dispersion interaction (zero point energy of coupled frequency‐dependent polarizabilities) cannot be described by DCPs, their mathematical form, together with parameter adjustment, can empirically capture attractive dispersion‐like forces to a rather high degree.…”

Problems, successes and challenges for the application of dispersion-corrected density-functional theory combined with dispersion-based implicit solvent models to large-scale hydrophobic self-assembly and polymorphism

“…[18] Further, it has now been established that even highly-parameterised functionals [19,20] do not describe the asymptotes of the London-dispersion energy correctly and that they still suffer from the same underlying problem as all conventional DFT approximations. [21] In the last decade, other promising approaches have been developed to tackle the dispersion problem, and they can be divided into three categories: van-der-Waals density functionals (vdW-DFs), [22,23,24,25] effective-core potentials (ECPs) that try to mimic dispersion effects, [26,27,28,29,30] and additive dispersion corrections. [31,32,33,34,35,36,37,38,39,40,41,42] Herein, we briefly outline only the most important aspects of these corrections; for detailed reviews of the advantages and disadvantages of the different approaches we refer the reader to Refs.…”

“…[26,27,28,29,30] The technical advantage of these methods is that ECPs are implemented in all standard quantum-chemistry codes and that they can be readily used. A disadvantage is that the potentials have to be fitted for every single element, which limits the variety of systems that can be treated with such methods.…”