Potential energy time-dependent molecular theory

These rules are quite obviously what one would expect on the basis of a first-order time-dependent perturbation theory approach to colhsional energy transfer in which the interaction potential is expanded only to first order in the molecular normal coordinates. There will certainly be many situations where such a simple picture is expected to fail. One may ask why these simple rules are even qualitatively successful in many cases. The answer may be that V-V energy-transfer processes which have been observed to date using laser techniques, have almost always been faster than V-T/R relaxation or they could not have been detected. (Among the obvious exceptions to this statement are and SO where laser... 

Chapter 3 treats nuclear motions on the adiabatic potential energy surfaces (PES). One of the most powerful and simplest means to study chemical dynamics is the so-called ab initio molecular dynamics (or the first principle dynamics), in which nuclear motion is described in terms of the Newtonian d3mamics on an ab initio PES. Next, we review some of the representative time-dependent quantum theory for nuclear wavepackets such as the multiconfigurational time-dependent Hartree approach. Then, we show how such nuclear wavepacket d3mamics of femtosecond time scale can be directly observed with pump>-probe photoelectron spectroscopy. 

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