Molecular Dynamics Beyond the Adiabatic Approximation: New Experiments and Theory

Abstract

Annu. Rev. Phys. Chem. 1985.36:277-320. Downloaded from arjournals.annualreviews.org by CORNELL UNIVERSITY on 05/27/06. For personal use only.u,,.(q, Q) = ~, ~'k(q ; Qo)zk(Q), 3.where the orthonormal electronic states ~'k arc defined by solving the electronic Schr6dingcr equation at a chosen reference configuration Q0 :The vibrational wavcfunctions Zk arc determined by a set of coupled equations with hamiltonian matrix elements Hk.k" = T~bk.k" + <~kIHe(Q)l~k'>. 5.www.annualreviews.org/aronline Annual Reviews Annu. Rev. Phys. Chem. 1985.36:277-320. Downloaded from arjournals.annualreviews.org by CORNELL UNIVERSITY on 05/27/06. For personal use only.

Dynamics and kinetics of molecular high Rydberg states in the presence of an electrical field: An experimental and classical computational study

“…It is well known that low lying Rydberg states of a vibrationally excited diatomic core can autoionize and there are extensive studies of the rate of such processes. 3,27,29-32,37,50-53 This is also seen in polyatomic molecules 33 and in the autodetachment of negative ions. 54 The only difference is that we are concerned with the promotion of the electron to the quasicontinum of Rydberg states rather than to the real continum of a free electron, and it is known 55 that matrix elements of the relevant type can be extrapolated across the threshold.…”

“…[29][30][31][32][33][34][35][36][37][38][39] We are cognizant of this incisive contribution, yet we do not consider that the results and the important insights that have been provided can be simply extrapolated to the regime of high n's of larger molecules. One reason that we already mentioned is that we are interested in the dynamics within the detection window, a process which requires coupling to low frequency motions of the core.…”

Chemical Reaction Dynamics Beyond the Born-Oppenheimer Approximation

“…I also follow the convention noted by Tully (17) that the term "adiabatic" representation, which has been used for eigenfunctions and eigenvalues of either H o = H el + H SO [see Tully (17) for definitions] or for only H el depending on the context, is used for the eigenfunctions and eigenvalues of H el alone unless otherwise noted (thus assuming that spin orbit interactions are not important in the particular dynamics being discussed). I further restrict this review to electronic nonadiabatic effects in chemical reactions; the influence of electronic nonadiabaticity on bound states in molecular spectroscopy can also be considerable, as detailed in several reviews (35)(36)(37)(38)(39). Finally, whenever there is a conical intersection involved in the dynamics, one should also account for geometric phase (40) in the Hamiltonian in the adiabatic representation; because neither this review nor the Tully review addresses this point adequately, I refer the reader to previous reviews on geometric phase (41)(42)(43)(44) and a beautiful recent review by Yarkony (22).…”

Accidental conical intersections in H2Cl+(1A′)

“…The classic paper by Longuet-Higgins in 1975 (1) appears to be definitive as to the existence of such intersections and their dimensionality. Since then, these intersections have become well established both from the theoretical and computational perspectives (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) and have important implications for the theory of reaction dynamics (13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Within a specified area, the existence of a conical intersection can be demonstrated without actually locating it, if one exploits the geometric phase factor (Berry's phase): the eigenvectors of the intersecting states change their signs on being transported in a closed curve around the point of intersection (23)(24)(25)(26)(27)(28).…”