We have performed DFT calculations in the CP2K package which is based on a hybrid Gaussian and plane-wave (GPW) basis set. The exchangecorrelation energy was approximated by the PerdewBurkeErnzerhof (PBE) parametrization of the generalized gradient approximation (GGA). A triple-ζ plus polarization (TZVP) basis set was chosen for the calculations. The energy cutoff was set at 700 Ry and numerically checked to yield force converged to 0.001 eV/ Å. The convergence criterion for the self-consistent DFT solution was 106 eV. A 2D periodic poisson solver was used to avoid spurious interactions between neighboring images in the perpendicular direction. Brillouin zone was sampled using Γ point only. We model the adsorption of the alkali atoms on a single-layer 2D TMD substrate.