Tree Root Systems In Eastern Nebraska

Nous avons le plaisir de vous inviter tous à la présentation de la base de données FAMA, qui aura lieu le 24 février prochain à 14h30 dans la salle Jeanne-Vielliard de l'IRHT (40, avenue d'Iéna). "FAMA (= Fama Auctorum Medii Aevi). Oeuvres latines médiévales à succès" est un projet né de la collaboration entre l'Ecole nationale des chartes (Pascale Bourgain) et l'IRHT (Dominique Stutzmann et Francesco Siri), développé entièrement à l'IRHT et financé par le mécénat. Il ressemble en une base de..

Structural Transitions and Global Minima of Sodium Chloride Clusters

In recent experiments on sodium chloride clusters structural transitions between nanocrystals with different cuboidal shapes were detected. Here we determine reaction pathways between the low energy isomers of one of these clusters, (NaCl)35Cl-. The key process in these structural transitions is a highly cooperative rearrangement in which two parts of the nanocrystal slip past one another on a {110} plane in a direction. In this way the nanocrystals can plastically deform, in contrast to the brittle behaviour of bulk sodium chloride crystals at the same temperatures; the nanocrystals have mechanical properties which are a unique feature of their finite size. We also report and compare the global potential energy minima for (NaCl)NCl- using two empirical potentials, and comment on the effect of polarization.Comment: extended version, 13 pages, 8 figures, revte