Bridge function for the dipolar fluid from simulation

摘要

The exact bridge function of the Lennard-Jones dipolar (Stockmayer) fluid is extracted from Monte Carlo simulation data. The projections _g ~(mnl)(r) onto rotational invariants of the non-spherically symmetric pair distribution function g(r,) are accumulated during simulation. Making intensive use of anisotropic integral equation techniques, the molecular Ornstein-Zernike equation is then inverted in order to derive the direct correlation function c ~(mnl)(r), the cavity function y ~(mnl)(r), the negative excess potential of mean force lny| ~(mnl)(r), and the bridge function b ~(mnl)(r) projections. b(r,) presents strong, non-universal anisotropies at high dipolar coupling. This simulation data analysis may serve as reference and guide for approximated bridge function theories of dipolar fluids and is a valuable step towards the case of more refined, nonlinear water-like geometries.