Potential energy landscape signatures of slow dynamics in glass forming liquids

We study the properties of local potential energy minima (inherent structur es') sampled by liquids at low temperatures as an approach to elucidating t he mechanisms of the observed dynamical slowing down observed as the glass transition temperature is approached. This onset of slow dynamics is accomp anied by the sampling of progressively deeper potential energy minima. Furt her, evidence is found in support of a qualitative change in the inherent s tructures sampled in a temperature range that includes the mode coupling cr itical temperature T-c, such that a separation of vibrational relaxation wi thin inherent structure basins from that due to inter-basin transitions bec omes valid at temperatures T < T-c, Average inherent structure energies do not show any qualitatively significant system size dependence. (C) 1999 Pub lished by Elsevier Science B.V. All rights reserved.