ABSTRACT
The size reduction brings an increase in unpaired electrons for the
atoms located at the surface. Since these unpaired electrons do not
participate to the bonding, it results in a decrease of the net cluster
cohesive energy. As mentioned for the surface reconstruction, the
cluster cohesive energy increases after moving the adatoms in order
to pair some of them. In this case, the the number of dangling bonds
decreases but the gain in energy is counterbalanced by the cost
of strain energy brought by the displacement of the atoms. In the
following, we discuss the geometry of the clusterswhen the dangling
bonds are entirely saturated by hydrogen at the surface. In this case,
the geometry of the cluster mimics the one observed in the whole
crystal.
