Van der Waals Density Functional With Corrected Long-Range Behavior
T. Thonhauser
Wake Forest University, Department of Physics, Winston-Salem, NC 27109
Email: thonhauser@wfu.edu
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 [1, 2, 3, 4]. We stay entirely true to the original design criteria of vdWDF, adhering to the exact same physical constraints. But, we take advantage of some freedom in defining the plasmon-dispersion model ωq, 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.
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