The Penetrable Square-Well Model: Extensive versus Non-Extensive Phases

0375825 - ÚCHP 2012 RIV GB eng J - Journal Article
Fantoni, R. - Malijevský, Alexandr - Santos, A. - Giacometti, A.
The Penetrable Square-Well Model: Extensive versus Non-Extensive Phases.
Molecular Physics. Roč. 109, 23-24 (2011), s. 2723-2736. ISSN 0026-8976. E-ISSN 1362-3028
R&D Projects: GA AV ČR IAA400720710
Grant - others:PRIN-COFIN(IT) 2007B58EAB; FIS(ES) 2010-16587
Institutional research plan: CEZ:AV0Z40720504
Keywords : penetrable square-well model * thermodynamic stability * phase diagram
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 1.819, year: 2011

The phase diagram of the penetrable square-well fluid is investigated through Monte Carlo simulations of various nature. This model was proposed as the simplest possibility of combining bounded repulsions at short scale and short-range attractions. We prove that the model is thermodynamically stable for sufficiently low values of the penetrability parameter, and in this case the system behaves similarly to the square-well model. For larger penetration, there exists an intermediate region where the system is metastable, with well-defined fluid-fluid and fluid-solid transitions, at finite size, but eventually it becomes unstable in the thermodynamic limit. We characterize the unstable non-extensive phase appearing at high penetrability, where the system collapses into an isolated blob of a few clusters of many overlapping particles each
Permanent Link: http://hdl.handle.net/11104/0208383