  We analyzed pattern formation and identified different phases in a system of
particles interacting through a non-monotonic short-range repulsive (r<r_c) and
long-range attractive (r>r_c) potential, using molecular-dynamics simulations.
Depending on parameters, the interaction potential models the interparticle
interaction in various physical systems ranging from atoms, molecules and
colloids to neutron stars and vortices in low-kappa type-II superconductors and
in recently discovered "type-1.5" superconductors. We constructed the phase
diagram "critical radius r_c - density n" and proposed a new approach to
characterization of the phases. Namely, we elaborated a set of quantitative
criteria in order to identify the different phases using the Radial
Distribution Function (RDF), the local density function, and the occupation
factor.
