The fundamental challenge remains for discriminating between metallic(M)and semiconducting(S)single-walled carbon nanotubes(SWNTs).We address this issue by studying the adsorptionof the isotropic atoms Xe,Kr,and a highly anisotropic molecule n-heptane on M-and S-SWNTs with density functional theory including many body dispersion forces.We find that the distinct polarizabilities of M-and S-SWNTs correspond to the significantly different physisorption properties,which are also strongly controlled by the SWNTs diameter,adsorption site,adsorption coverage,and adsorbates anisotropy.These findings essentially stem from the wavelike nature of charge density fluctuations in SWNTs.Particularly,these results allow us to rationalize the unusual √3 × √3R30° phase of Kr atoms on small gap M-SWNTs and the double desorption peak temperatures of n-heptane on M-SWNTs in experiments,and also propose then-heptane as an effective sensor for experimentally discriminating between M-and S-SWNTs.