By　means　of　cluster　models　coupled　with　density　functional　theory,　we　have　studied　the　hydroboration　of　the　Ge(100)(-2)　x　1　surface　with　BH3.　It　was　found　that　the　Ge(1　0　0)　surface　exhibits　rather　different　surface　reactivity　toward　the　dissociative　adsorption　of　BH3　compared　to　the　C(1　0　0)　and　Si(1　0　0)　surfaces.　The　strong　interaction　still　exists　between　the　as-formed　BH2　and　H　adspeices　although　the　dissociative　adsorption　of　BH3　on　the　Ge(I　0　0)　surface　occurs　readily,　which　is　in　distinct　contrast　to　that　on　the　C(1　0　0)　and　Si(1　0　0)　surfaces.　This　can　be　understood　by　the　electrophilic　nature　of　the　down　Ge　atom,　which　makes　it　unfavourable　to　form　a　Ge-H　bond　with　the　dissociating　proton-like　hydrogen.　Alternatively,　it　can　be　attributed　to　the　weak　proton　affinity　of　the　Ge(1　0　0)　surface.　Nevertheless,　the　overall　dissociative　adsorption　of　BH3　on　group　IV　semiconductor　surfaces　is　favourable　both　thermodynamically　and　kinetically,　suggesting　the　interesting　analogy　and　similar　diversity　chemistry　of　solid　surface　in　the　same　group.　(c)　2005　Elsevier　B.V.　All　rights　reserved.