Thermodynamic stability of soft-core Lennard-Jones fluids and their mixtures

Heyes, D. M.

Abstract

Thermodynamic stability of model single component and binary mixture fluids is considered with the Fisher–Ruelle (FR) stability criteria, which apply in the thermodynamic limit, and molecular dynamics (MD) simulation for finite periodic systems. Two soft-core potential forms are considered, ϕ 6,1 (r)=4[1/(a+r 6 ) 2 −1/(a+r 6 )] and ϕ 2,3 (r)=4[1/(a+r 2 ) 6 −1/(a+r 2 ) 3 ] , where r is the separation between the particle centers. According to FR these are unstable in the thermodynamic limit if a>a c =1/2 and a>a c =(7/32) 1/3 , respectively. MD simulations with single-component particles show, however, that this transition on typical simulation times is more gradual for finite periodic systems with variation in a on either side of a c . For a

Citation

Heyes, D. M. (2010). Thermodynamic stability of soft-core Lennard-Jones fluids and their mixtures. Journal of Chemical Physics, 132(6), 64504. https://doi.org/10.1063/1.3319510

• Journal Article Type: Article
• Online Publication Date: Feb 12, 2010
• Publication Date: Feb 14, 2010
• Deposit Date: Apr 10, 2014
• Journal: The Journal of Chemical Physics
• Print ISSN: 0021-9606
• Electronic ISSN: 1089-7690
• Publisher: AIP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 132
• Issue: 6
• Pages: 64504
• DOI: https://doi.org/10.1063/1.3319510
• Keywords: Fluid drops; Molecular dynamics; Boundary value problems; Drop coalescence; Thermodynamic properties
• Public URL: http://researchrepository.napier.ac.uk/id/eprint/6757