PERCOLATION AND PHASE-TRANSITIONS OF HARD-CORE PARTICLES ON LATTICES WITH PAIR INTERACTIONS

Using the Monte Carlo simulation method, we calculate the particle density, the density fluctuation F, The average energy U, the energy fluctuations Fu, the percolation ratio P, and the mean cluster size S as a function of p, where p=e /(e +1), with being the chemical potential, for hard-core particles on the plane triangular, square, and simple cubic lattices with pair interactions. In each studied case the singular point of F and Fu is consistent with the percolation transition point within numerical errors. Our results indicate that the phase transitions of the studied systems are percolation transitions. © 1990 The American Physical Society.