Entropy, Dynamics and Instantaneous Normal Modes in a Random Energy Model
Abstract
It is shown that the fraction f of imaginary frequency instantaneous normal modes (INM) may be defined and calculated in a random energy model(REM) of liquids. The configurational entropy S and the averaged hopping rate among the states R are also obtained and related to f, with the results R~f and S=a+b*ln(f). The proportionality between R and f is the basis of existing INM theories of diffusion, so the REM further confirms their validity. A link to S opens new avenues for introducing INM into dynamical theories. Liquid 'states' are usually defined by assigning a configuration to the minimum to which it will drain, but the REM naturally treats saddle-barriers on the same footing as minima, which may be a better mapping of the continuum of configurations to discrete states. Requirements of a detailed REM description of liquids are discussed.
Cite
@article{arxiv.cond-mat/0005160,
title = {Entropy, Dynamics and Instantaneous Normal Modes in a Random Energy Model},
author = {Tom Keyes},
journal= {arXiv preprint arXiv:cond-mat/0005160},
year = {2016}
}