Modeling of fluids and interfaces via synthesis of integral equations and Mayer-sampling cluster integral calculations

0854340 kofkeintellectual优点。本项目旨在发展和应用计算流体统计力学理论中出现的聚类积分的方法。使用的主要方法是Mayer抽样方法，该方法在先前的工作中得到了发展和改进。目前的工作主要集中在维里系数的计算，并有两种一般推力。首先，该项目旨在改进计算这些系数的方法。这里的努力考虑了更好地表征温度依赖性，更有效地分组簇以最大限度地减少计算工作量，并使用近似积分方程闭包来减少必要的Mayer采样积分的大小，从而减少计算中的误差。第二个项目目标是研究病毒处理在流体相表征中的性能并改进其应用。目的是为了更好地表征维里级数的收敛性，并确定如何应用它来近似定位汽液临界点，特别是应用于混合物。这项工作还着眼于开发可以改善维里级数应用范围的重新公式或近似值。更广泛的影响。这项研究的进展在化学热力学领域具有广泛影响的内在潜力。从分子模型快速过渡到宏观性质的能力可以促进分子模型的制定，从而更好地表征流体相。这反过来又可以在有用的条件范围内产生材料特性的真正预测能力，仅给定分子规格和热力学状态。因此，这项研究的结果将产生一种使能技术，可以以许多不可预见的方式在其他领域取得进展。至少，这项研究将消除对气相或超临界材料进行分子模拟的需要，而是允许通过基于分子的病毒处理进行更有效和准确的表征。这种能力可用于各种应用，如表征气相分子聚类，或相平衡计算执行吉布斯系综，或研究溶质分配在超临界流体；值得注意的是，所有这些功能对能源和环境应用都很重要。执行了几种特殊的传播形式，以确保这项工作很容易被其他人采用。面向图形的软件应用程序被开发并通过网络提供。本软件的不同版本分别设计为：(1)允许用户生成符合特定规格的集群，其形式适合他或她自己的计算机代码使用，或仅用于以图形形式呈现以供指导或思考；(2)利用本项目开发的方法计算任意电位的聚类积分和维里系数；(3)确定给定维里系数值的纯流体和混合物的临界点。

0854340KofkeIntellectual Merit. This project aims to develop and apply methods for calculating cluster integrals that appear in statistical mechanical theories of fluids. The primary method used is the Mayer sampling approach that was developed and refined in prior work. The present work is focused on the calculation of virial coefficients, and has two general thrusts. First, the project aims to improve methods for calculating these coefficients. Efforts here consider better characterization of the temperature dependence, more efficient grouping of the clusters to minimize the computational effort, and use of approximate integral equation closures to reduce the magnitude of the necessary Mayer sampling integrals and thereby reduce the error in their calculation. The second project goal is to study the performance and improve the application of the virial treatment in characterizing fluid phases. The aim is to better characterize the convergence of the virial series, and determine how it may be applied to approximately locate vapor liquid critical points, particularly as applied to mixtures. The work also looks to develop reformulations or approximants that can improve the range of application of the virial series.Broader Impact. Advances from this research have intrinsic potential for broad impact in chemical thermodynamics. The ability to rapidly move from a molecular model to its macroscopic properties can facilitate the formulation of molecular models that are better able to characterize fluid phases. This in turn can yield truly predictive capabilities in material properties over a useful range of conditions, given only molecular specifications and thermodynamic state. The results of this research would thus produce an enabling technology that can lead to progress in other fields in many unforeseen ways. At a minimum, this research will eliminate the need to ever perform a molecular simulation of a vapor phase or supercritical material, instead permitting a much more efficient and accurate characterization through a molecular based virial treatment. This capability can be useful for diverse applications, such as characterization of gas-phase molecular clustering, or phase equilibria calculations performed in the Gibbs ensemble, or study of solute partitioning in supercritical fluids; notably, all of these capabilities are important to energy and environmental applications.Several special forms of dissemination are performed to ensure that this work is readily adopted by others. Graphically oriented software applications are developed and made available via the web. Different versions of this software are, respectively, designed to: (1) permit the user to generate clusters meeting particular specifications, in a form suitable for use by his or her own computer codes, or simply for presentation pictorially for instruction or contemplation; (2) calculate cluster integrals and virial coefficients for arbitrary potentials using the methods being developed in the project; and (3) identify pure fluid and mixture critical points given values of the virial coefficients.