Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521-0444, USA.
J Chem Phys. 2011 May 7;134(17):174702. doi: 10.1063/1.3585677.
We report a perturbative density functional theory for quantitative description of the structural and thermodynamic properties of square-well fluids in the bulk or at inhomogeneous conditions. The free-energy functional combines a modified fundamental measure theory to account for the short-range repulsion and a quadratic density expansion for the long-range attraction. The long-correlation effects are taken into account by using analytical expressions of the direct correlation functions of bulk fluids recently obtained from the first-order mean-spherical approximation. The density functional theory has been calibrated by extensive comparison with simulation data from this work and from the literature. The theory yields good agreement with simulation results for the radial distribution function of bulk systems and for the density profiles of square-well fluids near the surfaces of spherical cavities or in slit pores over a broad range of the parameter space and thermodynamic conditions.
我们提出了一种微扰密度泛函理论，用于定量描述方阱流体在本体或非均匀条件下的结构和热力学性质。自由能泛函结合了修正的基本测量理论来描述短程排斥，以及二次密度展开来描述长程吸引。通过使用最近从一阶平均球近似中获得的本体流体的直接相关函数的解析表达式，考虑了长相关效应。该密度泛函理论已经通过与本工作和文献中的模拟数据的广泛比较进行了校准。该理论对于本体系统的径向分布函数以及在球形腔表面附近或狭缝孔中的方阱流体的密度分布在广泛的参数空间和热力学条件下与模拟结果吻合良好。
