Phase and glass transitions in short-range central potential model systems: the case of C60.
Extensive molecular dynamics simulations show that a short-range central potential, suited to model C60, undergoes a high temperature transition to a glassy phase characterized by the positional disorder of the constituent particles. Crystallization, melting, and sublimation, which also take place during the simulation runs, are illustrated in detail. It turns out that vitrification and the mentioned phase transitions occur when the packing fraction of the system-defined in terms of an effective hard-core diameter-equals that of hard spheres at their own glass and melting transition, respectively. A close analogy also emerges between our findings and recent mode coupling theory calculations of structural arrest lines in a similar model of protein solutions. We argue that the conclusions of the present study might hold for a wide class of potentials currently employed to mimic interactions in complex fluids (some of which are of biological interest), suggesting how to achieve at least qualitative predictions of vitrification and crystallization in those systems.
Abramo
Maria C
MC
Dipartimento di Fisica, Università degli Studi di Messina, Contrada Papardo, C.P. 50-98166 Messina, Italy.
Caccamo
Carlo
C
Costa
Dino
D
Ruberto
Romina
R