The Si(100) surface is modelled with slab models of with both (2×2) and (3×3) surface supercells, consisting of ten-layers of Si, where the bottom four-layers are fixed during the calculations. A vacuum region of 15Å is applied and a 3×3×1 k-points mesh is used throughout the calculations for all slab models. (2×2) supercell is applied to determine the saturation coverages of different surface terminations. (3×3) supercell is applied for precursor adsorption and ligand exchange reaction simulations.