Photodissociation snapshots

Figure 3, Wavepacket dynamics of the photodissociation of NOCl, shown as snapshots of the density (wavepacket amplitude squared) at various times, The coordinates, in au, are described in Figure b, and the wavepacket is initially the ground-state vibronic wave function vertically excited onto the 5i state. Increasing corresponds to chlorine dissociation. The density has been integrated over the angular coordinate. The 5i PES is ploted for the geometry, 9 = 127, the ground-state equilibrium value,...

By using the presented second-generation gas electron diffraction apparatus, it would also be possible to probe vibrational motion in real time. Especially when a molecule is photodissociated, a series of snapshots of a diffraction pattern would facilitate understanding the photodissociation process because it describes how a molecule vibrates in the course of the separation of two frag-... 

Figure 9.3 Photodissociation Spectra of ABC. A laser pulse transfers the ground state vibrational wavefunction to the repulsive electronically excited potential energy surface. The wavepacket moves and spreads (to, ti, <2, 3 snapshots) on the excited surface, being accelerated in the steepest descent direction (force is negative gradient of the potential) toward A + BCt products (where and f refer respectively to electronic and vibrational excitation). Information about the photodissociation mechanism may be obtained from the (structureless)...

Figure 23.10 shows the first snapshot obtained by the ion-imaging technique for the photodissociation of methyl iodide (see the paper by Chandler and Houston (1987)). The product detected is the methyl radical. The dissociation laser operated at 266 nm. At this energy it is known that the I fragment is formed in its first electronically excited state, the state. The... 

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