Adiabatic elimination in multidimensional diffusive barrier crossing

نویسندگان

  • Savely Rabinovich
  • Noam Agmon
چکیده

We consider the (reaction-coordinate) viscosity dependence of reaction-rate coefficients for the two-dimensional AgmonKosloff surface. We show that rate coefficients calculated from the Agmon-Hopfield sink-Smoluchowski equation are a lower bound, approaching asymptotically the two-dimensional result for fast reactive-mode diffusion. A modified equation, employing an effective potential in the spirit of a recent suggestion by the Karpov group. yields a promising approximation over most of the viscosity range.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Steepest Descent Path Study of Electron-Transfer Reactions†

A nonadiabatic steepest descent path method is developed as a qualitative tool to analyze and characterize three different kinetic regimes of electron transfer. In this approach, Miller’s semiclassical instanton solution and Pechukas’ self-consistent treatment of nonadiabatic coupling are applied to the path integral representation of the two-state diffusion equation. The resulting steepest des...

متن کامل

Exploring the dynamics of dimer crossing over a Kramers type potential.

We explore the escape rate of a dimer crossing a potential barrier using both analytical and numerical approaches. We find that for small coupling strength k, the barrier hopping can be well approximated by a two step reaction scheme where one monomer hops over the barrier and is then followed by the other. In this regime the escape rate increases with k showing that the cooperativity between m...

متن کامل

Entropy Generation of Double Diffusive Natural Convection in a Three Dimensional Differentially Heated Enclosure

Entropy generation of double diffusive natural convection in a three dimensional differentially heated enclosure has been performed numerically. Vertical walls of enclosure are heated differentially and remaining walls are adiabatic. The obtained results were presented via iso-concentration, iso-temperatures, velocity vector projection, particle trajectories, velocity profiles, iso-entropy, loc...

متن کامل

Coil-to-stretch transition, kink formation, and efficient barrier crossing of a flexible chain.

We study the thermally activated barrier crossing of a linear, flexible chain (polymer) under the Kramers bistable potential using the multidimensional barrier crossing theory and the functional integral method. We find that above a critical chain length or below a critical chain spring constant the chain at the barrier top undergoes coil-to-stretch transition, resulting in the formation of a k...

متن کامل

Microscopic derivation of an adiabatic thermodynamic transformation

We obtain macroscopic adiabatic thermodynamic transformations by space-time scalings of a microscopic Hamiltonian dynamics subject to random collisions with the environment. The microscopic dynamics is given by a chain of oscillators subject to a varying tension (external force) and to collisions with external independent particles of “infinite mass”. The effect of each collision is to change t...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2005