  We study phase transformations in finite nuclei as a function of interaction
parameters. The signature of a transition is given by invariant correlational
entropy that reflects the sensitivity of an individual many-body state to
changes of external parameters; peaks in this quantity indicate the critical
regions. This approach is able to reveal the pairing phase transition, identify
the isovector and isoscalar pairing regions and determine the role of other
interactions. We show the examples of the phase diagram in the parameter space.
