Journal ArticleDOI
Canonical dynamics: Equilibrium phase-space distributions
Reads0
Chats0
TLDR
The dynamical steady-state probability density is found in an extended phase space with variables x, p/sub x/, V, epsilon-dot, and zeta, where the x are reduced distances and the two variables epsilus-dot andZeta act as thermodynamic friction coefficients.Abstract:
Nos\'e has modified Newtonian dynamics so as to reproduce both the canonical and the isothermal-isobaric probability densities in the phase space of an N-body system. He did this by scaling time (with s) and distance (with ${V}^{1/D}$ in D dimensions) through Lagrangian equations of motion. The dynamical equations describe the evolution of these two scaling variables and their two conjugate momenta ${p}_{s}$ and ${p}_{v}$. Here we develop a slightly different set of equations, free of time scaling. We find the dynamical steady-state probability density in an extended phase space with variables x, ${p}_{x}$, V, \ensuremath{\epsilon}\ifmmode \dot{}\else \.{}\fi{}, and \ensuremath{\zeta}, where the x are reduced distances and the two variables \ensuremath{\epsilon}\ifmmode \dot{}\else \.{}\fi{} and \ensuremath{\zeta} act as thermodynamic friction coefficients. We find that these friction coefficients have Gaussian distributions. From the distributions the extent of small-system non-Newtonian behavior can be estimated. We illustrate the dynamical equations by considering their application to the simplest possible case, a one-dimensional classical harmonic oscillator.read more
Citations
More filters
Journal ArticleDOI
Self‐diffusion in n‐alkane fluid models
P. Padilla,Søren Toxvaerd +1 more
TL;DR: In this paper, an isotropic united atom (UA) model as well as anisotropic unitedatom (AUA) models have been used to represent the molecular interactions and the sensitivity of the self-diffusion coefficient to the shape of the intermolecular potential and the torsion potential has been analyzed.
Journal ArticleDOI
Symplectic algorithm for constant-pressure molecular dynamics using a Nosé–Poincaré thermostat
Jess B. Sturgeon,Brian B. Laird +1 more
TL;DR: In this paper, the authors present a new algorithm for isothermal-isobaric molecular-dynamics simulation using an extended Hamiltonian with an Andersen piston combined with the Nose-Poincare thermostat.
Journal ArticleDOI
Structural anomalies for a three dimensional isotropic core-softened potential
TL;DR: The region in the pressure-temperature phase diagram of the structural anomaly englobes the region of the diffusion anomaly that is larger than the region limited by the temperature of maximum density.
Journal ArticleDOI
Interface Water on TiO2 Anatase (101) and (001) Surfaces: First-Principles Study with TiO2 Slabs Dipped in Bulk Water
TL;DR: In this article, the authors investigated the TiO2 anatase (101) and (001) interfaces dipped in bulk water on the atomic scale by first-principles density-functional molecular dynamics simulations.
Journal ArticleDOI
Dynamical motions of lipids and a finite size effect in simulations of bilayers.
TL;DR: Reorientational correlation functions for the slowly relaxing phosphorus-glycerol hydrogen, phosphorus-nitrogen vectors, and more rapidly relaxing CH vectors in the aliphatic chains are equivalent for the 72 and 288 lipid simulations.