Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

Abstract

Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B3N3H6) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.

Tuning dissociation using isoelectronically doped graphene and hexagonal boron nitride: Water and other small molecules

“…It is well known that bond strengths and adsorption energies vary from one functional to the next 80,81 and PBE in particular neglects van der Waals (vdW) dispersion forces and does not include exact exchange. Indeed, previous work on similar systems to those considered here, namely, the physisorption of water on h-BN 82 and on BN doped benzene, 83 has shown that vdW interactions can be important. Here, however, we are concerned with strongly bonded chemisorption structures of the dissociated fragments of water and the other molecules involving an energy scale of several electronvolts.…”

Jastrow correlation factor for periodic systems

“…It has been found in the literature 5,6,[16][17][18] that a Taylor expansion in electron-electron separation captures the most important short-ranged isotropic inter-particle correlations, and so here we review that expansion. Writing the Jastrow correlation function as a Taylor series around particle coalescence results in an expression…”

The Many Faces of Heterogeneous Ice Nucleation: Interplay Between Surface Morphology and Hydrophobicity

“…For instance, an extension of the present study to realistic clean metal surfaces needs to account for the orientational dependence of the water molecules on the surface and polarization effects. Fitting water-surface interaction potentials to density functional theory or higherlevel electronic structure theories is one way to take such effects into account and work in our group in this direction is ongoing [103][104][105][106] . Furthermore, it has been shown that dissociation of water molecules occurs at reactive metal surfaces so that the overlayers can be comprised of water-hydroxyl mixtures [107][108][109][110] .…”