In addition to the two surface terminations of Si(100) described above, we further investigate the possible formation of SiNx/Si(100) and H:SiNx/Si(100) substrates. These can form via surface Si atoms reacting with plasma generated •N and •H radicals, which can migrate through the Si surface. These surfaces were generated with ab initio MD calculations and full details are given in the Supporting Information. The resulting SiNx/Si(100) and H;SiNx/Si(100) are shown in Figure and Figure . The precursors RuCp2 and CoCp2 adsorb at the SiNx/Si(100) and H:SiNx/Si(100) surfaces with computed adsorption energies summarized in Table . The preferred binding mode is the horizontal mode, the same as on the other substrates, and this adsorption mode shows computed adsorption energies of -0.47eV for RuCp2 and -0.76eV for CoCp2 on H:SiNx/Si(100) substrate and -0.53eV for and -1.74eV for CoCp2 on SiNx/Si(100) substrate. Again, CoCp2 shows a stronger interaction at the surface compared to RuCp2. The larger adsorption energy on the SiNx termination compared to the H:SiNx termination may reflect undercoordinated atoms on the surface terminating layer. On the NHx-terminated Si(100) surface, RuCp2 shows endothermic reactions for elimination of both Cp ligands. On the contrary, NHx-terminations can promote the 1 st Cp ligand elimination for CoCp2 with a computed overall reaction energy at -0.21eV and the reaction energies to eliminate both Cp ligands on the NHx-terminated Si(100) surface is endothermic. . The computed activation barrier for 1 st H transfer step is a moderate 0.73eV. This difference is due to the stronger Ru-C bond strength compared to Co-C bond strength. This is also observed on the elimination of Cp ligands on NHx-terminated Ru and Co surfaces, where CoCp2 has exothermic reaction energies and low activation barriers on NHx-terminated Co(001) and Co(100) surfaces, but RuCp2 has endothermic reaction energies and high activation barriers on NHxterminated Ru(001) and Ru(100) surfaces.