Selective Adsorption Resonances in the Scattering of n-H2 p-H2 n-D2 and o-D2 from Ag(111)

Abstract

Diffractive and rotationally mediated selective adsorption scattering resonances are reported for $n$-${\mathrm{H}}_2$ $p$-${\mathrm{H}}_2$ $n$-${\mathrm{D}}_2$ and $o$-${\mathrm{D}}_2$ on Ag(111). Small resonance shifts and line-width differences are observed between $n$-${\mathrm{H}}_2$ and $p$-${\mathrm{H}}_2$ indicating a weak orientation dependence of the laterally averaged ${\mathrm{H}}_2$/Ag(111) potential. The $p$-${\mathrm{H}}_2$ and $o$-${\mathrm{D}}_2$ levels were used to determine the isotropic component of this potential, yielding a well depth of ∼ 32 meV.