title: Nonperturbative effect of attractive forces in viscous liquids.
abstract: We study the role of the attractive intermolecular forces in the viscous regime of a simple glass-forming liquid by using computer simulations. To this end, we compare the structure and the dynamics of a standard Lennard-Jones glass-forming liquid model with and without the attractive tail of the interaction potentials. The viscous slowing down of the two systems is found to be quantitatively and qualitatively different over a broad density range, whereas the static pair correlations remain close. The common assumption that the behavior of dense nonassociated liquids is determined by the short-ranged repulsive part of the intermolecular potentials dramatically breaks down for the relaxation in the viscous liquid regime.
authors.affiliation: Laboratoire des Colloïdes, Verres et Nanomatériaux, Université Montpellier II and CNRS, 34095 Montpellier, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Berthier
authors.forename: Gilles
authors.initials: G
authors.lastname: Tarjus