INHERENT STRUCTURES AND 2-STAGE MELTING IN 2 DIMENSIONS

A large-scale study of the ''inherent structures'' (IS) associated wit h equilibrium two-dimensional Lennard-Jones systems is presented. The results validate, for simple 2D fluids, an essential premise of inhere nt-structures theory: there are consistent, qualitative differences be tween the IS associated with distinct equilibrium phases. The hexatic IS show free dislocations plus some nonpercolating grain boundaries. T he liquid IS always contain percolating grain boundaries, but no evide nce of free disclinations. Our results are consistent with the disloca tion-unbinding scenario for the hexatic phase, but leave open the ques tion of the microscopic melting mechanism leading to the isotropic liq uid.