  It is shown that negative heat capacity in nanoclusters is an artifact of
applying equilibrium thermodynamic formalism on a small system trapped out of
equilibrium in a particular structural motif representing only part of the
energetically available phase space volume. Trapping may occur in either the
canonical or microcanonical ensemble, but it is unavoidable in the
microcanonical. A more general consequence of trapping is that all macroscopic
quantities determined for nanoclusters will depend on the initial conditions.
