Improved proton-transfer barriers with van der Waals density functionals: Role of repulsive non-local correlation
- 22 June 2022
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 156 (24), 244106
- https://doi.org/10.1063/5.0095128
Abstract
Proton-transfer (PT) between organic complexes is a common and important biochemical process. Unfortunately, PT energy barriers are difficult to accurately predict using density functional theory (DFT); in particular, using the generalized gradient approximation (GGA) tends to underestimate PT barriers. Moreover, PT typically occurs in environments where dispersion forces contribute to the cohesion of the system; thus, a suitable exchange-correlation functional should accurately describe both dispersion forces and PT barriers. This paper provides benchmark results for the PT barriers of several density functionals, including several variants of the van der Waals density functional (vdW-DF). The benchmark set comprises small organic molecules with inter- and intra-molecular PT. The results show that replacing GGA correlation with a fully non-local vdW-DF correlation increases the PT barriers, making it closer to the quantum chemical reference values. In contrast, including non-local correlations with the Vydrov-Voorhis method or dispersion-corrections at the DFT-D3 or the Tkatchenko-Scheffler level has barely any impact on the PT barriers. Hybrid functionals also increase and improve the energies, resulting in an excellent performance of hybrid versions of vdW-DF-cx and vdW-DF2-B86R. For the formic acid dimer PT system, we analyzed the GGA exchange and non-local correlation contributions. The analysis shows that the repulsive part of the non-local correlation kernel plays a key role in the PT energy barriers predicted with vdW-DF. Published under an exclusive license by AIP Publishing.Funding Information
- Norges Forskningsråd (302362)
This publication has 70 references indexed in Scilit:
- Optimized norm-conserving Vanderbilt pseudopotentialsPhysical Review B, 2013
- Assessment of Theoretical Procedures for Calculating Barrier Heights for a Diverse Set of Water-Catalyzed Proton-Transfer ReactionsThe Journal of Physical Chemistry A, 2012
- Density functional theory with London dispersion correctionsWIREs Computational Molecular Science, 2011
- Nonlocal van der Waals density functional: The simpler the betterThe Journal of Chemical Physics, 2010
- A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-PuThe Journal of Chemical Physics, 2010
- Accurate description of van der Waals complexes by density functional theory including empirical correctionsJournal of Computational Chemistry, 2004
- First-principles calculation of the electronic, dielectric, and dynamical properties ofPhysical Review B, 2003
- Toward reliable density functional methods without adjustable parameters: The PBE0 modelThe Journal of Chemical Physics, 1999
- From ultrasoft pseudopotentials to the projector augmented-wave methodPhysical Review B, 1999
- Self-Consistent Equations Including Exchange and Correlation EffectsPhysical Review B, 1965