https://doi.org/10.1351/goldbook.I02971
A situation in which the freedom of molecules of @[email protected] to move about the surface is limited. @[email protected] is immobile when \(k\ T\) is small compared to \(\Delta E\), the energy barrier separating adjacent sites. The @[email protected] has little chance of migrating to neighbouring sites and such adsorption is necessarily localized.