document: First-principles calculations have clarified the electronic structure and stability of the W@Si12 cluster under O2 molecule adsorption and reaction. Our results show that the W-encapsulated Si12 hexagonal prism cage is very inert to oxidation. The O2 molecule only weakly adsorbs onto the cluster at relatively low temperatures, in the range of several tens meV. However, significant reaction barriers (0.593–1.118 eV) for the O2 molecule on the cluster are identified on different adsorption sites, nevertheless, these reaction paths are spin forbidden reactions according to Wingerʼs spin selection rule. These results imply that O2 readily desorb from the cluster surface rather than dissociate and oxide the W@Si12 cluster upon excitations. In high temperature and high pressure conditions, the O2 molecules may dissociate on the preferential edge site by overcoming a significantly large energy barrier.
doc_bio_tags: O O O O O B I I I O O O B O B O B O B O O O O O O O O O O O O O O B O B O O O O O O B O O B I O O O O O O O O O B O O O O O B O O O B O O O O B O O O B O O B I I O O B I I I O O O O B O O O O B O O O O O O O O B O O O B I I I I I O B O O O O O O O O O B I I I I I
extractive_keyphrases: adsorption cluster electronic structure and stability high temperature and high pressure conditions low temperatures o2 overcoming a significantly large energy barrier oxidation reaction spin forbidden reactions wingerʼs spin selection rule
abstractive_keyphrases: 0.593–1.118 ev first-principles calculations o2 molecule adsorption and reaction significant reaction barriers w-encapsulated si12 hexagonal prism cage w@si12 cluster