By　means　of　density　functional　theory　in　conjunction　with　periodic　slab　models,　coverage-dependent　behavior　for　chemical　functionalization　of　the　semiconductor　X　(100)　(X　=　C,　Si,　and　Ge)　surface　by　traditional　cycloadclition　of　transition　metal　oxides　(OsO4　and　RuO4)　has　been　investigated.　We　found　that　the　transition-metal-mediated　oxygen　transfer　reaction　for　cycloadclition　of　OsO4　and　RuO4　onto　X　(100)　is　quite　favorable.　The　adsorption　energies　decrease　as　the　coverage　is　increased,　and　the　band　gap　is　widened　or　reduced　depending　on　both　the　type　of　model　molecules　and　the　coverage.　Furthermore,　it　is　feasible　to　form　organic　layer　films　of　transition　metal　oxides　onto　the　semiconductor　X　(100)　surface　as　reflected　by　the　high　adsorption　energies　at　the　saturated　coverage,　which　could　lead　to　new　hybrid　multifunctional　materials.　In　addition,　interestingly,　two　distinct　and　competitive　monolayer　structures　are　simultaneously　observed　on　both　the　Si　(100)　and　the　Ge　(100)　surfaces,　but　only　one　stable　monolayer　geometry　is　found　on　the　C　(100)　surface,　indicating　the　flexibility　of　controlling　the　self-assembled　molecular　binding　configuration　using　transition　metal　oxides　on　the　semiconductor　X　(100)　surface.　It　is　hoped　that　our　results　may　help　to　seek　appropriate　chemical　modification　methods　to　widen　the　application　fields　of　the　group　IV　semiconductor-based　hybrid　materials.