Percolation Transitions in Sticky Disk Systems. A Molecular Dynamics Study

Molecular dynamics computer simulation was performed on the systems consisting of 100 two dimensional particles interacting with the hard core square well potential. Calculations were performed for various combinations of the parameters defining the attractive part of the potentials and for various densities. The pairs e and A, denoting the depth and width of the potential well, were chosen in such a way that the systems approached Baxter’s limit of sticky or adhesive potential with infinite depth and zero width of the well, provided that the product A exp(e/kT) remained finite. The results of the simulation gave support to the claims based on the analysis of higher order virial coefficients that the system of adhesive particles does not possess thermodynamic stability. The results show that the approach of the system towards equilibrium slows down when approaching the limit of stickiness and, besides, systems close to the sticky limit show a tendency to aggregation and collapse towards the crystal structure, which raises doubts about the regularity of the percolation problem of sticky systems