General issues and the case of CO on metals

Molecular adsorbates provide an increasingly complex set of challenges to surface structure determination, the complexity growing steeply with the number of atoms within the molecule. A special problem is also presented by hydrogen atoms which are present in the majority of chemically interesting molecules, but to which all 

One structural parameter of potential interest in the adsorption of simple diatomic molecules, such as CO, NO and N2, is the intramolecular bondlength. Much of the motivation for studying such adsorbates is related to the way adsorption modifies the chemistry of these species as the basis for heterogeneous catalysis. Many such reactions involve scission of the intramolecular bond, and if the adsorption is of the 

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