Contents

20 March 1998
Vol 279, Issue 5358

About The Cover

Calculated potential energy surface for the chemical reaction O2 + O2 O3 + O. This reaction is only possible if a reactant oxygen molecule has at least 25 quanta of vibrational energy. See the special section on reaction dynamics beginning on 1875 as well as the Editorial (1831), News story (1847), and related Reports (pages 1913 and 1946). [Image: D. Lauvergnat, D. M. Benoit, D. C. Clary, University College London]