High inertness of W@Si12 cluster toward O2 molecule

► We investigated the O2 molecule adsorption on W@Si12 cluster. ► The dissociation barrier of the O2 molecule on W@Si12 was examined. ► The MEP and the inertness of W@Si12 toward O2 are identified. ► The spin-state-dependent kinetic processes are discussed. ► Other factors were also discussed for the inertness of the cluster studied.