On the generalized Kramers problem with oscillatory memory friction

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.479347· OSTI ID:349347

Reigada, R ^[1]; Romero, A H ^[2]; Lindenberg, K ^[3]; Sancho, J M ^[4]

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1. Department of Chemistry and Biochemistry 0340, University of California San Diego, La Jolla, California 92093-0340 (United States)
2. Department of Chemistry and Biochemistry 0340 and Department of Physics, University of California San Diego, La Jolla, California 92093-0340 (United States)
3. Department of Chemistry and Biochemistry 0340 and Institute for Nonlinear Science, University of California San Diego, La Jolla, California 92093-0340 (United States)
4. Departament dEstructura i Constituents de la Materia, Universitat de Barcelona, Avenida Diagonal 647, E-08028 Barcelona (Spain)

The time-dependent transmission coefficient for the Kramers problem exhibits different behaviors in different parameter regimes. In the high friction regime it decays monotonically ({open_quotes}nonadiabatic{close_quotes}), and in the low friction regime it decays in an oscillatory fashion ({open_quotes}energy-diffusion limited{close_quotes}). The generalized Kramers problem with an exponential memory friction exhibits an additional oscillatory behavior in the high friction regime ({open_quotes}caging{close_quotes}). In this paper we consider an oscillatory memory kernel, which can be associated with a model in which the reaction coordinate is linearly coupled to a nonreactive coordinate, which is in turn coupled to a heat bath. We recover the nonadiabatic and energy-diffusion-limited behaviors of the transmission coefficient in appropriate parameter regimes, and find that caging is not observed with an oscillatory memory kernel. Most interestingly, we identify a new regime in which the time-dependent transmission coefficient decays via a series of rather sharp steps followed by plateaus ({open_quotes}stair-like{close_quotes}). We explain this regime and its dependence on the various parameters of the system. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 349347
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 111; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CHEMICAL REACTION KINETICS
DIFFUSION
FRICTION
OSCILLATIONS
THERMODYNAMICS