https://doi.org/10.1140/epjb/e2006-00353-0
Free energy landscape from path-sampling: application to the structural transition in LJ38
1
Service de Recherches de Métallurgie Physique, Commissariat à l'Énergie Atomique/Saclay, 91191 Gif-sur-Yvette, France
2
Laboratoire de Chimie et Physique Quantiques, IRSAMC, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France
Corresponding author: a Manuel.Athenes@cea.fr
Received:
31
May
2006
Revised:
27
July
2006
Published online:
22
September
2006
We introduce a path-sampling scheme that allows equilibrium state-ensemble averages to be computed by means of a biased distribution of non-equilibrium paths. This non-equilibrium method is applied to the case of the 38-atom Lennard-Jones atomic cluster, which has a double-funnel energy landscape. We calculate the free energy profile along the Q4 bond orientational order parameter. At high or moderate temperature the results obtained using the non-equilibrium approach are consistent with those obtained using conventional equilibrium methods, including parallel tempering and Wang-Landau Monte Carlo simulations. At lower temperatures, the non-equilibrium approach becomes more efficient in exploring the relevant inherent structures. In particular, the free energy agrees with the predictions of the harmonic superposition approximation.
PACS: 07.05.Tp – Computer modeling and simulation / 36.40.Ei – Phase transitions in clusters / 64.70.Pf – Glass transitions / 82.60.Lf – Thermodynamics of solutions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006