Workhorse minimally empirical dispersion-corrected density functional with tests for weakly bound systems: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">r</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msup><mml:mi>SCAN</mml:mi><mml:mo>+</mml:mo><mml:mrow><mml:mi>rVV</mml:mi><mml:mn>10</mml:mn></mml:mrow></mml:mrow></mml:math>
Jinliang Ning, Manish Kothakonda, James W. Furness, Aaron D. Kaplan, Sebastian Ehlert, Jan Gerit Brandenburg, John P. Perdew, Jianwei Sun
Abstract
$\mathrm{SCAN}+\mathrm{rVV}10$ has been demonstrated to be a versatile van der Waals (vdW) density functional that delivers good predictions of both energetic and structural properties for many types of bonding. Recently, the ${\mathrm{r}}^{2}\mathrm{SCAN}$ functional was devised as a revised form of SCAN with improved numerical stability. In this work, we refit the rVV10 functional to optimize the ${\mathrm{r}}^{2}\mathrm{SCAN}+\mathrm{rVV}10$ vdW density functional and test its performance for molecular interactions and layered materials. Our molecular tests demonstrate that ${\mathrm{r}}^{2}\mathrm{SCAN}+\mathrm{rVV}10$ outperforms its predecessor $\mathrm{SCAN}+\mathrm{rVV}10$ in both efficiency (numerical stability) and accuracy. This good performance is also found in lattice-constant predictions. In comparison with benchmark results from higher-level theories or experiments, ${\mathrm{r}}^{2}\mathrm{SCAN}+\mathrm{rVV}10$ yields excellent interlayer binding energies and phonon dispersions for layered materials.