Phase transitions of quadrupolar fluids
- Department of Chemistry, University of Lethbridge, Lethbridge, Alberta, Canada, T1K 3M4 (CANADA)
- Brookhaven National Laboratory, Upton, New York 11973 (United States)
- Department of Chemistry, University of Maine, Orono, Maine 04469 (United States)
Gibbs ensemble simulations are reported for Lennard-Jones particles with embedded quadrupoles of strength Q{sup {asterisk}}=Q/({epsilon}{sigma}{sup 5}){sup 1/2}=2.0 where {epsilon} and {sigma} are the Lennard-Jones parameters. Calculations revealing the effect of the dispersive forces on the liquid{endash}vapor coexistence were carried out by scaling the attractive r{sup {minus}6} term in the Lennard-Jones pair potential by a factor {lambda} ranging from 0 to 1. Liquid{endash}vapor coexistence is observed for all values of {lambda} including {lambda}=0 for Q{sup {asterisk}}=2.0, unlike the corresponding dipolar fluid studied by van Leeuwen and Smit {ital et al.} [Phys. Rev. Lett. {bold 71}, 3991 (1993)] which showed no phase transition below {lambda}=0.35 when the reduced dipole moment {mu}{sup {asterisk}}=2.0. The simulation data are analyzed to estimate the critical properties of the quadrupolar fluid and their dependence on the strength {lambda} of the dispersive force. The critical temperature and pressure show a clear quadratic dependence on {lambda}, while the density is less confidently identified as being linear in {lambda}. The compressibility is roughly linear in {lambda}. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 530061
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 1 Vol. 107; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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