Accession Number : ADA294650

Title :   A Theory for Time Correlation Functions in Liquids.

Descriptive Note : Technical rept. May 94-May 95,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA DEPT OF CHEMISTRY

Personal Author(s) : Cao, Jianshu ; Voth, Gregory A.

PDF Url : ADA294650

Report Date : 30 MAY 1995

Pagination or Media Count : 34

Abstract : A theory for time correlation functions in liquids is developed based on the optimized quadratic approximation for liquid state potential energy functions. The latter approximation leads to the rigorous mathematical definition of inherent structures in liquids and their vibrational fluctuations, in turn leading to the concept of inherent normal modes in the liquid state. These normal modes are called "optimized normal modes". Unlike normal modes based on instantaneous liquid state configurations, the optimized normal modes are stable, having real valued frequencies, and each inherent liquid state structure has a different set of modes associated with it. By including a single phenomenological decay function which captures the average transition rate between the different sets of normal modes, velocity time correlation functions and dynamical friction kernels for solute bonds can be predicted in good agreement with direct molecular dynamics simulation results.

Descriptors :   *LIQUIDS, *ELECTROCHEMISTRY, VELOCITY, OPTIMIZATION, MOLECULAR VIBRATION, RATES, VARIATIONS, CHEMICAL BONDS, CORRELATION, CONFIGURATIONS, SOLUTES, QUADRATIC EQUATIONS, DECAY, FUNCTIONS(MATHEMATICS).

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE