Perspective: Advances and challenges in treating van der Waals dispersion forces in density functional theory

Abstract

Electron dispersion forces play a crucial role in determining the structure and properties of biomolecules, molecular crystals, and many other systems. However, an accurate description of dispersion is highly challenging, with the most widely used electronic structure technique, density functional theory (DFT), failing to describe them with standard approximations. Therefore, applications of DFT to systems where dispersion is important have traditionally been of questionable accuracy. However, the last decade has seen a surge of enthusiasm in the DFT community to tackle this problem and in so-doing to extend the applicability of DFT-based methods. Here we discuss, classify, and evaluate some of the promising schemes to emerge in recent years. A brief perspective on the outstanding issues that remain to be resolved and some directions for future research are also provided.

Low-pressure phase diagram of crystalline benzene from quantum Monte Carlo

“…Our results indicate that Pbca and P2 1 /c are the most stable structures in the studied pressure ranges. These results are consistent with the experimental phase diagram proposed by 52 vdW-DF2, 50 rVV, 56,57 obk8, B86R, ob86, 35,53 DFCx, 55 DFC09, and DF2C09 54 vdW functionals. The right panel illustrates the results of conventional DFT including PBE, 49 LDA, 58 and BLYP.…”

“…At lower pressures vdW-DF1, 52 vdW-DF2, 50 and DFcx 55 V (P) points for Pbca phase are close to experiments. With increasing the pressure, the P2 1 /c V (P) curves computed with vdW-DF2, 50 obk8, 35,53 rVV, 56,57 and B86R 35,53 are close to experimental points. The rVV functional has a different nonlocal correlation kernel, whereas other vdW functionals are the modified versions of vdW-DF1 or vdW-DF2.…”

“…We employed vdW-DF1, 52 vdW-DF2, 50 vdW-DF-obk8, vdW-DF-ob86, vdW-DF2-B86R, 35,53 vdW-DF-C09, vdW-DF2-C09, 54 vdW-DF-cx, 55 and vdW-rVV 56,57 vdW functionals. Except rVV functional, the nonlocal term in the other vdW functionals is either vdW-DF1 52 or vdW-DF2.…”

“…We obtain static and dynamic phase diagrams where the phonon contribution to the free energy is included. We employ different vdW functionals 35 and compare them with conventional DFT functionals. We perform QMC calculations to obtain the static enthalpy-pressure phase diagram of crystalline benzene.…”

Cooperative Interplay of van der Waals Forces and Quantum Nuclear Effects on Adsorption: H at Graphene and at Coronene

“…For the treatment of vdW interactions, many schemes have recently been developed which could in principle be applied to this system (see for example ref 5 ). Most results in the present manuscript have been obtained with the so-called "DFT-D3" functional (specifically PBE-D3), 38 however, the key results of our study are not particularly sensitive to the specific vdW scheme used and as we show in the supporting material the same conclusions are reached with the other vdW inclusive approaches.…”