Improved metallic surface properties using a new van der Waals density functional

An incorrect description of van der Waals (vdW) interactions for different problems using popular density functional theory (DFT) is found in many cases, especially where long-range van der Waals interactions are present. Metallic surfaces are such systems. Physical properties of surfaces such as surface energy and work function can be affected by the long-range van der Waals interaction present at the surface barrier. In this work we explore the performance of the new vdW-corrected non-local density functional SCAN$+$rVV10$^{\mathrm{1}}$ for such surfaces. We find that, when the new meta-GGA functional SCAN is combined with the non-local rVV10 method, it can not only give a better description of the van der Waals interaction in molecules and layered materials, but can be equally used as a more versatile competitor of LDA for metal surfaces. 1.Versatile van der Waals Density Functional Based on a Meta-Generalized Gradient Approximation, H. Peng, Z. Yang, J. P. Perdew, J. Sun, Phys. Rev. X~6, 041005 (2016). Acknowledgments: NSF under DMR-1305135, CNS-09-5884, and by DOE under DE-SC0012575, DE-AC02-05CH11231