arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1202.4276cond-mat.soft
收藏

硬球的吸附:根据势分布定理的结构和有效密度

Adsorption of hard spheres: structure and effective density according to the potential distribution theorem

L. L. Lee, G. Pellicane

摘要:

我们提出了一种新的有效密度通过潜在的分布定理。这些密度是为了能够将均匀流体的自由能映射到非均匀流体的自由能上。电势分布定理给出了在外部(壁)电势的作用下将测试粒子插入到浴分子中所需的功。该插入功W_ins可以从蒙特卡罗(MC)模拟(例如,从Widom的测试粒子技术)或从分析理论获得。由此构造伪密度,使得当它们的值代入均匀流体状态方程(例如硬球化学势的Carnahan-Starling方程)时,MC非均匀插入功得以再现。我们描述了硬球/硬壁系统在中密度到高密度(ρ^*= 0.5745到0.9135)下的赝密度行为。为此,我们采用Groot等人的MC数据。伪密度显示出与单重态密度异相(相反)的振荡行为。我们还建立了一个新的基于闭包的密度泛函理论(星函数基密度泛函理论),它可以精确描述MC的密度分布和插入功。对硬球吸附的几种情况建立了一个可行的理论。

英文摘要:

We propose a new type of effective densities via the potential distribution theorem. These densities are for the sake of enabling the mapping of the free energy of a uniform fluid onto that of a nonuniform fluid. The potential distribution theorem gives the work required to insert a test particle into the bath molecules under the action of the external (wall) potential. This insertion work W_ins can be obtained from Monte Carlo (MC) simulation (e.g. from Widom's test particle technique) or from an analytical theory. The pseudo-densities are constructed thusly so that when their values are substituted into a uniform-fluid equation of state (e.g. the Carnahan-Starling equation for the hard-sphere chemical potentials), the MC nonuniform insertion work is reproduced. We characterize the pseudo-density behavior for the hard spheres/hard wall system at moderate to high densities (from ρ^*= 0.5745 to 0.9135). We adopt the MC data of Groot et al. for this purpose. The pseudo-densities show oscillatory behavior out of phase (opposite) to that of the singlet densities. We also construct a new closure-based density functional theory (the star-function based density functional theory) that can give accurate description of the MC density profiles and insertion works. A viable theory is established for several cases in hard sphere adsorption.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑