Chimie

The Environmental Effects Assessment Panel Report for 2006 205 REVIEWERS OF THE 2006 UNEP EFFECTS ASSESSMENT PANEL Professor Ayite-Lo Nohende Ajavon Atmospheric Chemistry Laboratory FDS/Université de Lome BP 1515 Lome TOGO Phone:+ 228-225 5094 Fax:+ 228-221 8595 Mobile+ 228-904-1593/944 9444 Home+ 228-226-9170 noajavon@ tg. refer. org Dr. Pedro J. Aphalo Department of Biological and Environmental Sciences Plant Biology/Plant Ecology PO Box 65 00014 University of Helsinki Finland pedro. aphalo@ ...

The methodology of ab initio molecular dynamics, wherein finite-temperature dynamical trajectories are generated by using forces computed "on the fly" from electronic structure calculations, has had a profound influence in modern theoretical research. Ab initio molecular dynamics allows chemical processes in condensed phases to be studied in an accurate and unbiased manner, leading to new paradigms in the elucidation of microscopic mechanisms, rationalization of experimental data, and testable predictions of new phenomena. The purpose of this work is to give a brief introduction to the technique and to review several important recent developments in the field. Several illustrative examples showing the power of the technique have been chosen. Perspectives on future directions in the field also will be given.

Dipole polarizabilities of individual ions and molecules are computed from first principles in three condensed-phase systems: pure water, pure hydrofluoric acid, and an equimolar mixture of water and hydrofluoric acid in which HF is mostly ionized. We find that the polarizability of fluorine and oxygen centers varies linearly with the value of the bond order, which measures the local degree