  We have studied the adsorption of NO on small Rh clusters, containing one to
five atoms, using density functional theory in both spin-polarized and
non-spin-polarized forms. We find that NO bonds more strongly to Rh clusters
than it does to Rh(100) or Rh(111); however, it also quenches the magnetism of
the clusters. This (local) effect results in reducing the magnitude of the
adsorption energy, and also washes out the clear size-dependent trend observed
in the non-magnetic case. Our results illustrate the competition present
between the tendencies to bond and to magnetize, in small clusters.
