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Variational transition state theory (VTST) is applied for the first time to a chemical reaction in a liquid. The theory provides accurate estimates of reaction rates and leads to well defined microscopic friction functions. The structure of the optimized planar dividing surface provides insight into the range of solute–solvent interactions for which there is an appreciable effect on the reaction dynamics. The VTST method also allows for separation of the frictional effects of solvent translation, rotation, and stretch modes. The numerical cost is less than an analogous molecular dynamics reactive flux computation and the insight gained is greater. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Details a stochastic model to emulate intramolecular vibrational relaxation in molecules undergoing isomerization. Punctuation of the Hamiltonian flow at random times by an exchange of vibrational kinetic energies; Salient features of rate processes in real molecules reproduced by the model.

Examines the application of harmonic quantum transition state theory to isomerize stilbene in liquid ethane. Estimate of quantum correction to classical reaction rate; Effects of dense solvent on reaction rate estimate; Application of classical molecular dynamics in classical reaction rate.

Reports on theoretical studies on the rate of isomerization of trans-stilbene from the first excited electronic state based on the potential energy surface. Harmonic RRKM calculations and molecular dynamics and Monte Carlo based classical rates for deuterated isotopes of stilbene and hexane clusters of stilbene of varying size.

Presents theoretical computations of the rate in the gas and liquid phases of unimolecular reactions. Indications of previous theoretical and experimental investigations; Presentation of theoretical computations of the rate in the gas and liquid phases.

A theoretical investigation of the experimental measurements of the isomerization rate of trans-stilbene in liquids is presented. Monte Carlo and molecular dynamics simulations of the reaction indicate that the predominant solvent effect is in raising the isomerization barrier in the potential of mean force as the solvent density is increased. Dynamic friction effects are small. Good agreement is obtained between the numerical and experimental rates. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Variational transition state theory (VTST) is applied for the first time to a realistic simulation of a reaction in a liquid. Rate information is obtained from Monte Carlo thermal classical centroid averages of second derivatives of the full potential of interaction. A well defined friction function is computed and found to be in excellent agreement with previous approximate prescriptions leading to identical rate constants. [ABSTRACT FROM AUTHOR]