Physisorption interaction of H₂ with simple metals

Calculations of the physisorption interaction between a H2-molecule and simple metal surfaces are reported. The physisorption wells of simple and noble metals having the same s-electron densities are markedly different. The former are shallower because there is no contribution of d-electrons to the Van der Waals force. The physisorption energies are found to depend strongly on the bulk density, varying from 25 meV (Al) to 2.7 meV (K). Results for three Al surfaces show a face dependence due to the different work functions that may be measurable. © 1986.