van der Waals density functional with corrected long-range behavior

A new van der Waals density functional, i.e. vdW-DF3, has been developed by maintaining an accurate balance between short- and long-range contributions to the non-local correlation in the original vdW-DF scheme. We stay entirely true to the original design criteria of vdW-DF, adhering to the exact same physical constraints. But, we take advantage of some freedom in defining the plasmon-dispersion model ω_q, which allows us to significantly improve the asymptotic behavior and the resulting calculated C₆ coefficients, overcoming the problem of unreliable C₆ coefficients from previous vdW-DF functionals. Our functional predicts very well the binding energies (<5% error) and separation for molecular dimers of commonly used reference datasets (such as S22, A24, X40, S66 etc.); performance in solids, layered structures, and noble gas dimers is also good.