Peres lattices in nuclear structure
  A method by Peres is used to draw spectra of the interacting boson model as lattices in the plane of energy versus an arbitrary observable average (or variance). Ordered (disordered) lattices are signatures of regularity (chaos) in both quantum and classical dynamics. The method is also apt to disclose exact or approximate dynamical symmetry. 
Michal Macek, Pavel Str\'ansk\'y, Pavel Cejnar