Abstract
In this article techniques for including dispersion interactions within density functional
theory are examined. In particular comparisons are made between four popular methods:
dispersion corrected DFT, pseudopotential correction schemes, symmetry adapted perturbation
theory, and a non-local density functional - the so called Rutgers-Chalmers van
der Waals density functional (vdW-DF). The S22 benchmark data set is used to evaluate
the relative accuracy of these methods and factors such as scalability and transferability
are also discussed. We demonstrate that vdW-DF presents an excellent compromise
between computational speed and accuracy and lends most easily to full scale application
in solid materials. This claim is supported through a brief discussion of a recent
large scale application to H2 in a prototype metal organic framework material (MOF),
Zn2BDC2TED. The vdW-DF shows overwhelming promise for first-principles studies of
physisorbed molecules in porous extended systems; thereby having broad applicability for
studies as diverse as molecular adsorption and storage, battery technology, catalysis and
gas separations.
