Europhys. Lett, 48 (4), pp. 415-420 (1999)
Order and disorder in hard-sphere packings
P. Richard 1, A. Gervois 2, L. Oger 1and J.-P. Troadec 1
1 Groupe Matière Condensée et Matériaux, UMR CNRS 6626,
Université de Rennes I
35042 Rennes Cedex, France
2 Service de Physique Théorique, Direction des Sciences de la Matière, CEA/Saclay
91191 Gif-sur-Yvette Cedex, France
(received 22 March 1999; accepted in final form 10 September 1999)
PACS. 64.60Cn - Order-disorder transformations; statistical mechanics of model systems.
PACS. 05.20 - Classical statistical mechanics.
PACS. 64.70Dv - Solid-liquid transitions.
We study the crystallisation of hard-sphere systems and compare the resulting packings with packings belonging to the stable branch of the phase diagram. This comparison is done by studying the distribution of a local bond order parameter which gives precise information on the structure and allows to detect without ambiguity the presence of fcc or hcp crystallisation in the packing. We have found, as expected, that the fcc symmetry is more stable than the hcp symmetry in crystallised systems. Furthermore, the fraction of hcp clusters in the system decreases as the propensity to crystallise increases. The method developed here for hard-sphere systems can be applied to any kind of soft-sphere potential systems.
Copyright EDP Sciences