ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We present a class of closures specifically designed to satisfy the zero-separation theorems for the correlation functions y(r) (the cavity function), γ(r)=h(r)−C(r) (the indirect correlation), and B(r) (the bridge function) at coincidence r=0 for soft-sphere pair potentials. The rationale is to ensure the correct behavior of these correlation functions inside the core r〈σ. Since the coincidence theorems implicate the thermodynamic properties of the bulk fluid: the isothermal compressibility, the internal energy and the chemical potentials, we can hopefully enforce consistency between the structure and thermodynamic properties. We solve the Ornstein–Zernike equation for the Lennard-Jones molecules where plentiful Monte Carlo data are available for testing. It turns out that not only consistency is achieved, we also obtain accurate structures: the pair correlation function g(r), the cavity function, and the bridge function for wide ranges of fluid states (0.72〈T*〈1.5, ρ*〈0.9). Comparison with MC data attests to the accuracy. The closure of the zero-separation type (ZSEP), is sufficiently robust and flexible to ensure not only fulfillment of the zero-separation theorems but also pressure consistency. Success with the Lennard-Jones potential implies its applicability to other similar soft-sphere potentials. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.471522
