General features of the energy landscape in Lennard-Jones-like model liquids

Features of the energy landscape sampled by supercooled liquids are numerically analyzed for several Lennard-Jones-like model systems. The properties of quasisaddles (minima of the square gradient of potential energy W=\delV\(2)), are shown to have a direct relationship with the dynamical behavior, confirming that the quasisaddle order extrapolates to zero at the mode-coupling temperature T(MCT). The same result is obtained either analyzing all the minima of W or the saddles (absolute minima of W), supporting the conjectured similarity between quasisaddles and saddles, as far as the temperature dependence of the properties influencing the slow dynamics is concerned. We find evidence of universality in the shape of the landscape: plots for different systems superimpose into master curves, once energies and temperatures are scaled by T(MCT). This allows to establish a quantitative relationship between T(MCT) and potential energy barriers for Lennard-Jones-like systems, and suggests a possible generalization to different model liquids. (C) 2003 American Institute of Physics.