  A new implementation is proposed for including van der Waals interactions in
Density Functional Theory using the Maximally-Localized Wannier functions. With
respect to the previous DFT/vdW-WF method, the present DFT/vdW-WF2 approach,
which is based on the simpler London expression and takes into account the
intrafragment overlap of the localized Wannier functions, leads to a
considerable improvement in the evaluation of the $C_6$ van der Waals
coefficients, as shown by the application to a set of selected dimers.
Preliminary results on Ar on graphite and Ne on the Cu(111) metal surface
suggest that also the $C_3$ coefficients, characterizing molecule-surfaces van
der Waals interactions are better estimated with the new scheme.
