Condensed Matter Physics, 2015, vol. 18, No. 4, 43603
DOI:10.5488/CMP.18.43603
arXiv:1512.07795
Title:
StokesEinstein relation and excess entropy scaling law in liquid Copper
Author(s):

N. Jakse
(Sciences et Ingénierie des Matériaux et Procédés, UMR CNRS 5266, Grenoble Université Alpes, BP 75, 38402 SaintMartin d'Héres Cedex, France)
,


A. Pasturel
(Sciences et Ingénierie des Matériaux et Procédés, UMR CNRS 5266, Grenoble Université Alpes, BP 75, 38402 SaintMartin d'Héres Cedex, France)

We report an ab initio study of structural and dynamic properties of liquid copper as a function of temperature.
In particular, we have evaluated the temperature dependence of the selfdiffusion coefficient from the velocity autocorrelation function
as well the temperature dependence of the viscosity from the transverse current correlation function. We show that LDA based results are
in close agreement with experimental data for both the selfdiffusion coefficient and the viscosity over the temperature range investigated.
Our findings are then used to test empirical approaches like the StokesEinstein relation and the excess entropy scaling law widely used in the
literature. We show that the StokesEinstein relation is valid for the liquid phase and that the excess entropy scaling law proposed by Dzugutov
is legitimate only if a selfconsistent method for determining the packing fraction of the hard sphere reference liquid is used within the
CarnahanStarling approach to express the excess entropy.
Key words:
liquid copper, StokesEinstein relation, universal scaling laws, ab initio molecular dynamics
PACS:
61.25.Mv, 61.20.Ja, 66.10.x
