@article {4817,
	title = {A semiclassical study of the photodissociation dynamics of a coupled two-surface model of HCl+ by an intense laser field in the long-wavelength limit},
	journal = {Journal of Chemical Physics},
	volume = {113},
	number = {6},
	year = {2000},
	note = {ISI Document Delivery No.: 344XTTimes Cited: 7Cited Reference Count: 39},
	month = {Aug},
	pages = {2124-2133},
	type = {Article},
	abstract = {The photodissociation of HCl+ on two coupled potential surfaces is studied in the long wavelength regime with a semiclassical method employing classical trajectories and a hopping algorithm. Dissociation probabilities, product kinetic energy distributions, and branching ratios are presented. In addition, two mechanisms are introduced to explain trends in these properties. One mechanism produces large product kinetic energies and is an extension to two-coupled surfaces of the "wagging tail" mechanism seen in a previous one-surface study [M. Thachuk and D. M. Wardlaw, J. Chem. Phys. 102, 7462 (1995)]. The other mechanism is an extended barrier-suppression mechanism and accounts for the bulk of the product kinetic energy distribution, and in particular rationalizes the low energy part of these distributions as well as the branching ratios. It is shown that most of the trajectories undergo at most one nontrivial hop before dissociating so that the dynamics is dominated by the motion near the barrier to dissociation. This provides a simple, intuitive model for understanding the overall dynamics. (C) 2000 American Institute of Physics. [S0021-9606(00)00130-6].},
	keywords = {ABOVE-THRESHOLD-DISSOCIATION, ALIGNMENT, COHERENT CONTROL, COULOMB EXPLOSION, H-2(+), HARMONIC-GENERATION, MOLECULAR-IONS, NM, ORDER, RESONANCE-ENHANCED IONIZATION, TRANSITIONS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000088786900011},
	author = {Gill, R. and Yanagawa, R. and Thachuk, M.}
}
@article {4417,
	title = {A semiclassical approach to intense-field above-threshold dissociation in the long wavelength limit. II. Conservation principles and coherence in surface hopping},
	journal = {Journal of Chemical Physics},
	volume = {109},
	number = {14},
	year = {1998},
	note = {ISI Document Delivery No.: 125BETimes Cited: 28Cited Reference Count: 24},
	month = {Oct},
	pages = {5747-5760},
	type = {Article},
	abstract = {This paper is a companion to our recently published semiclassical formalism for treating time-dependent Hamiltonians [J. Chem. Phys, 105, 4094 (1996)], which was applied to study the dissociation of diatomic ions in intense laser fields. Here two fundamental issues concerning this formalism are discussed in depth: conservation principles and coherence. For time-dependent Hamiltonians, the conservation principle to apply during a trajectory hop depends upon the physical origin of the electronic transition, with total energy conservation and nuclear momentum conservation representing the two limiting cases. It is shown that a]applying an inappropriate scheme leads to unphysical features in the kinetic energy of the dissociation products. A method is introduced that smoothly bridges the two limiting cases and applies the physically justified conservation scheme at all times. It is also shown that the semiclassical formalism can predict erroneous results if the electronic amplitudes for well-separated hops are added coherently. This is a fundamental problem with the formalism which leads to unphysical results if left unattended. Alternative schemes are introduced for dealing with this problem and their accuracies are assessed. Generalization of the well-known Landau-Zener formula to the time-dependent Hamiltonian case is derived, which allows one to significantly decrease the computational overhead involved with the numerical implementation of the semiclassical method. Finally, we show that in strong-field molecular dissociation a trajectory can {\textquoteright}{\textquoteright}surf" a moving avoided crossing. In this case the hopping probability is a sensitive function of the interference between two closely spaced avoided crossing regions. (C) 1998 American Institute of Physics.},
	keywords = {COULOMB EXPLOSION, DIATOMIC-MOLECULES, ENHANCED, H-2(+), IONIZATION, LASER FIELDS, MODEL, MOLECULAR-DYNAMICS, PHOTODISSOCIATION, QUANTUM DECOHERENCE, TRANSITIONS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000076216900008},
	author = {Thachuk, M. and Ivanov, M. Y. and Wardlaw, D. M.}
}
