  We present a new scheme to include the van der Waals (vdW) interactions in
approximated Density Functional Theory (DFT) by combining the Quantum Harmonic
Oscillator model with the Maximally Localized Wannier Function technique. With
respect to the recently developed DFT/vdW-WF2 method, also based on Wannier
Functions, the new approach is more general, being no longer restricted to the
case of well separated interacting fragments. Moreover, it includes higher than
pairwise energy contributions, coming from the dipole--dipole coupling among
quantum oscillators. The method is successfully applied to the popular S22
molecular database, and also to extended systems, namely graphite and H$_2$
adsorbed on the Cu(111) metal surface (in this case metal screening effects are
taken into account). The results are also compared with those obtained by other
vdW-corrected DFT schemes.
