Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0904.4922

"Isomorphs" in liquid state diagrams

Nicoletta Gnan·Thomas B. Schrøder·Ulf R. Pedersen·Nicholas P. Bailey·Jeppe C. Dyre
View original source ↗Read source document ↗Export metadata ↓

Also available from

Abstract

A liquid is termed strongly correlating if its virial and potential energy thermal equilibrium fluctuations in the NVT ensemble are more than 90% correlated [Phys. Rev. Lett. 100, 015701 (2008)]. The fluctuations of a strongly correlating liquid are well approximated by those of an inverse power-law intermolecular potential. Building on this fact we here define "isomorphic lines" in the state diagram of a strongly correlating liquid. It is shown from computer simulations of the Kob-Andersen binary Lennard-Jones liquid that no aging is associated with jumps between two isomorphic points. Isomorphic state points have the same excess entropy, the same reduced average relaxation time, the same (reduced) dynamics, and the same scaled radial distribution functions. Finally we calculate the equation for isomorphs in the virial / potential energy diagram for Lennard-Jones type liquids and show that all such 12-6 liquids have the same isomorphs; these may be scaled into a master isomorph.

Explore related subjects

cond-mat.soft

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Nicoletta Gnan, Thomas B. Schrøder, Ulf R. Pedersen, Nicholas P. Bailey, Jeppe C. Dyre. 2009-05-04. "Isomorphs" in liquid state diagrams. https://doi.org/10.1063/1.3265957

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Reciprocal theorem for ion-releasing colloidal particles

We describe a generalization of the reciprocal theorem for particles suspended in electrolyte solutions and subjected to an electric field that could be either applied or emerged spontaneously. Attention is focused on catalytic colloids that release ions. The power of the generalization is to capture the effect of formation of a secondary cloud around a catalytic particle, which is equivalent to accounting for an excess charge $Q$ of a system. Our results show that the propulsion speed of catalytic particles has an extra contribution proportional to $Q$ and an external field $E_{\infty}$. The derived equation for $Q$ reveals that its sign is defined by the difference in the ion diffusivity and the magnitude is controlled by the average flux of ions from the surface. We demonstrate the application of the generalized theorem to electro- and diffusiophoresis of homogeneously releasing ions passive particles, as well as to a self-propulsion of inhomogeneous active particles (microswimmers). It is shown that whilst in some situations the extra term in the reciprocal theorem vanishes or has a little effect on the particle mobility, in many others it may dramatically change its magnitude, and even sign. In addition, the relevance of our results for microswimmer interactions is discussed briefly.

cond-mat.soft↗
arXiv2026

Multigeometric Breathing Mode Framework for viruses

The estimation of the breathing mode frequency for viral capsids remains a persistent challenge across literature which spawned various frameworks and methodologies. However, discrepancies were observed between the experimental Low Frequency Raman Scattering (LFRS) and calculated pre-existing values. To solve this discrepancy, we propose a framework which is developed to determine the breathing-mode frequency by modelling the virus as a macroscopic coupled harmonic oscillator. By integrating mass-loading directly into the classical elastodynamic equations, this model yields an analytical expression that couples the system's total inertia with its specific geometry. Moreover, the viruses are segregated according to their geometries into three coordinates to acquire their respective geometric eigen values. Here we illustrate how the proposed Multigeometric Breathing mode Framework for Virus (MBFV) outperforms prior models by yielding closer values than the pre-existing frameworks upon validating against LFRS.

cond-mat.soft↗
arXiv2026

Insight into ordering at nematic twist-bend interfaces

Twist-bend nematics formed by achiral particles support heliconical domains of opposite handedness. Using Monte Carlo and molecular dynamics simulations of repulsive bent particles, we study the interface between two such domains. Rather than a gradually untwisting texture, we find a density-modulated splay-bend-twist structure. The density modulation is along the helix axis with a period of approximately half the bulk pitch, while the twist is locally enhanced in magnitude, alternates in sign, and vanishes only on an undulating surface. An explicit director interpolation shows how gradients along the helix axis and across the interface combine to produce an undulating zero-twist surface.

cond-mat.soft↗