Van der Waals Interactions in DFT Made Easy by Wannier Functions

Ubiquitous van der Waals interactions between atoms and molecules are important for many molecular and solid structures. These systems are often studied from first principles using the density functional theory (DFT). However, the commonly used DFT functionals fail to capture the essence of van der Waals effects. Most attempts to correct for this problem have a basic semiempirical character, although computationally more expensive first principles schemes have been recently developed. We here describe a novel approach, based on the use of the maximally localized Wannier functions, that appears to be promising, being simple, efficient, accurate, and transferable (charge polarization effects are naturally included). The results of test applications to small molecules and bulk graphite are presented.

Figure 1

Binding energy of the ${\mathrm{Ar}}_2$ dimer, as a function of the Ar-Ar distance, using the standard DFT-revPBE calculation and including the VdW corrections, compared to the reference, experimental value [26].