COMPUTER-SIMULATIONS OF DENSE HARD-SPHERE SYSTEMS

We present comprehensive results of large-scale molecular dynamics and Monte Carlo simulations of systems of dense hard spheres at volume fr action phi along the disordered, metastable branch of the phase diagra m from the freezing-point phi(f) to random close packing volume phi(c) . It is shown that many previous simulations contained deficiencies ca used by crystallization and finite-size effects. We quantify the degre e of local crystallization through an order parameter and study it as a function of time and initial conditions to determine the necessary c onditions to obtain truly random systems. This ordering criterion is u sed to show that previous methods employed to ascertain the degree of randomness are inadequate. A careful study of the pressure is also car ried out along the entire metastable branch. In the vicinity of the ra ndom-close packing fraction, we show that the pressure scales as (phi( c)-phi)(-gamma), where gamma = 1 and phi(c) = 0.644 +/- 0.005. Contrar y to previous studies, we find no evidence of a thermodynamic glass tr ansition. (C) 1996 American Institute of Physics.