2007/02/02 by Eric D. Chisolm, Chisolm, Eric D., Giulia De Lorenzi-Venneri +3
Chemical Engineering · Computer Science · Physics and Astronomy · #Current (fluid) #FOS: Physical sciences #Monatomic ion #Nonlinear Dynamics and Pattern Formation #Physics #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Statistical Mechanics (cond-mat.stat-mech) #Statistical physics #Thermodynamic properties of mixtures #Thermodynamics #cond-mat.stat-mech
paper · pdf · doi:10.48550/arxiv.cond-mat/0702051
published in arXiv (Cornell University) (Cornell University) · 17 pages, no figures, minor corrections
openalex publication_date 2007/02/02 · arxiv created 2007/05/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We consider for a monatomic liquid the density and current autocorrelation functions from the point of view of the Vibration-Transit (V-T) theory of liquid dynamics. We also consider their Fourier transforms, one of which is measured by X-ray and neutron scattering. In this description, the motion of atoms in the liquid is divided into vibrations in a single characteristic potential valley, called a random valley, and nearly-instantaneous transitions called transits between valleys. The theory proposes a Hamiltonian for the vibrational motion, to be corrected to take transits into account; this Hamiltonian is used to calculate the autocorrelation functions, giving what we call their vibrational contributions. We discuss the multimode expansions of the autocorrelation functions, which provide a physically helpful picture of the decay of fluctuations in terms of n-mode scattering processes; we also note that the calculation and Fourier transform of the multimode series are numerically problematic, as successive terms require larger sums and carry higher powers of the temperature, which is a concern for the liquid whose temperature is bounded from below by melt. We suggest that these problems are avoided by directly computing the autocorrelation functions, for which we provide straightforward formulas, and Fourier transforming them numerically.