Phase transitions of simple systems. (Q2426418)

The emergence, coexistence of many phases and the dynamics of phase transitions in small closely packed atomic systems is examined both theoretically and with the computer assistance. The basic concepts are grounded in the thermodynamics of purely classical (no mention of quantum theory) atomic systems, allowed to form clusters of various sizes (like e.g. from 13, 16, 55, 147, 891 or 1289). Clusters are interpreted purely classically as composed of atoms that are bound by nearest neighbor (classical) couplings, mostly of van der Waals, Lenard-Jones and Morse type. The central concept of the description is that of voids: they appear as well organized (through shapes of their boundaries) void structures within atomic clusters and are responsible for detailed characteristics of cluster phases and their dynamics (kinetic viewpoint). Transitions between crystalline, glassy and fluid states are allowed. A number of transitional equilibria plus coexistence of a few phase equilibria can arise as well. That allow for an insight into how bulk properties of matter evolve from those of small systems.