When the cluster excitation energy is such that the hopping between di
fferent isomers becomes energetically allowed, the power spectrum corr
esponding to the very long-time dynamics is dominated by the 1/f-noise
. The emergence of 1/f-noise is indicative of the absence of any chara
cteristic time scales in the structure/conformation cluster dynamics.
The 1/f-noise portion of the power spectrum covers all frequencies bel
ow the characteristic cluster modes and is essentially temperature ind
ependent once the cluster has ''melted''.