All DFT calculations were performed using the Perdew-Burke-Ernzerhof (PBE) functional as implemented in all-electron FHI-aims code , with 'tight' basis sets and integration grids. The Kohn-Sham self-consistent cycle was converged to 10 -6 eV in energy and 10 -5 electrons in density. The input α 0 and C 6 for the MBD Hamiltonian were obtained from the rescaling of the reference free-atom values with the ratio of Hirshfeld volumes of a free-atom and atom-in-molecule computed at the PBE level: