Subpicosecond experiments on molecular vibration

Vibrational motion on the subpicosecond time scale of a transient collision intermediate has been observed through its striking effects upon differential and total cross sections in inelastic and reactive processes in atom- and ion-molecule collisions. Transient charge transfer processes that form a short-lived diatomic ion and then return to the original potential energy surface are shown to be efficient paths to high vibrational excitation of molecular targets. Similar effects should be observable in a large number of collision systems. (Auth.)