Asymmetric fluid criticality. II. Finite-size scaling for simulations.
The vapor-liquid critical behavior of intrinsically asymmetric fluids is studied in finite systems of linear dimensions L focusing on periodic boundary conditions, as appropriate for simulations. The recently propounded "complete" thermodynamic (L--> infinity) scaling theory incorporating pressure mixing in the scaling fields as well as corrections to scaling [Phys. Rev. E 67, 061506 (2003)] is extended to finite L, initially in a grand canonical representation. The theory allows for a Yang-Yang anomaly in which, when L--> infinity, the second temperature derivative (d2musigma/dT2) of the chemical potential along the phase boundary musigmaT diverges when T-->Tc-. The finite-size behavior of various special critical loci in the temperature-density or (T,rho) plane, in particular, the k-inflection susceptibility loci and the Q-maximal loci--derived from QL(T,<rho>L) is identical with <m2>2L/<m4>L where m is identical with rho-<rho>L--is carefully elucidated and shown to be of value in estimating Tc and rhoc. Concrete illustrations are presented for the hard-core square-well fluid and for the restricted primitive model electrolyte including an estimate of the correlation exponent nu that confirms Ising-type character. The treatment is extended to the canonical representation where further complications appear.
Kim
Young C
YC
Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.
Fisher
Michael E
ME
D003198:Computer Simulation; D004735:Energy Transfer; D007700:Kinetics; D008962:Models, Theoretical; D010507:Periodicity; D044367:Phase Transition; D011312:Pressure; D012212:Rheology / Q000379:methods*; D012996:Solutions / Q000737:chemistry*; D013696:Temperature
D012996:Solutions