Correcting density functionals for dispersion interactions using pseudopotentials

We present a two-channel dispersion-corrected atom-centered potential (DCACP) method for correcting BLYP and PBE density functionals for long-range dispersion. The approach, designated DCACP2, is tested on the S22X5 test set and on isomers of the water hexamer. The DCACP2 method provides a significantly improved description of the interaction energies at distances beyond Req than does the single-channel DCACP procedure.