U.S.-Turkey Cooperative Research: Global Optimization of Transferable Molecular Step Potential Functions

0421849 Elliott描述：该项目支持俄亥俄州阿克伦市阿克伦大学化学工程系的Richard Elliott博士和土耳其伊斯坦布尔Bogazici大学化学工程系的Mehmet Camurdan博士以及土耳其伊斯坦布尔Koc大学工业工程系的Metin Turkay博士之间的合作研究。 研究的目的是开发一种通用工具，用于推断分子相互作用参数的基础上的物理性质数据的蒸汽压，密度，扩散率，汽液平衡，液液平衡。 这些物理性质的表征在化学过程分析和模拟以及化学产品设计中起着重要作用。 表征这些性质的可转移的分子间相互作用将允许预测的性质和结构活性的新化合物的关系。详细的分子结构，包括分支，环，和键角的分子动力学模拟，是用来区分异构体和立体效应的基础。基于这些预测，工程师将能够在实验合成工作之前“通过计算机”识别有利的潜在化合物。 智力优势：研究方法基于不连续分子动力学和热力学微扰理论（DMD/TPT）。DMD/TPT将分子势分解为离散的步骤，类似于方阱势，但具有多于一个吸引阱。通过TPT，吸引势的表征被简化为一个可逼近的全局优化问题。台阶的深度是简单的连续参数，并且预测的物理性质的偏差包括目标函数。最佳步长的选择需要一定程度的整数规划。站点直径的优化在需要新的模拟方面带来显著的损失。开发该系统的全局优化策略对优化方法提出了新的挑战。 虽然DMD/TPT特别适合这种优化，但也可以通过导数和直方图重新加权方法来探测物理性质对连续电位中参数的敏感性。随着连续势的研究取得进展，人们将认识到需要一种可靠有效的方法来优化可转移的势参数。更广泛的影响：这将包括综合研究和教育以及国际交流。PI是化学工程热力学文本的合著者，并且已经整合了以前NSF支持的相关结果，他的教学应该发展到包括需要广泛分子洞察力的产品设计。预计化工产品设计在课程中的重要性将逐步提高。这项合作将展示一个国际研究的范例，充分利用双方的利益和能力。

0421849 ElliottDescription: This project supports a collaborative research between Dr. Richard Elliott, Department of Chemical Engineering, Akron University, Akron, Ohio and Dr. Mehmet Camurdan, Chemical Engineering Department, Bogazici University, Istanbul, Turkey and Dr. Metin Turkay, Industrial Engineering Department, Koc University, in Istanbul, Turkey. The objective of the research is to develop a general tool for inferring molecular interaction parameters based on physical property data for vapor pressure, density, diffusivity, vapor-liquid equilibria, and liquid-liquid equilibria. Characterizations of physical properties like these play a major role in chemical process analysis and simulation and chemical product design. Characterizing these properties in terms of transferable molecular interactions will permit predictions of properties and structure-activity-relations for new compounds. Molecular dynamics simulation of the detailed molecular structure, including branching, rings, and bond-angles, is used as the basis for distinguishing isomeric and steric effects. Based on these predictions, engineers will be able to identify favorable prospective compounds "in silico," prior to experimental synthetic efforts. Intellectual Merits: The methodology of the research is based on Discontinuous Molecular Dynamics and Thermodynamic Perturbation Theory (DMD/TPT). DMD/TPT breaks the molecular potential down into discrete steps, similar to a square-well potential but with more than one attractive well. Through TPT, the characterization of the attractive potential is reduced to an approachable global optimization problem. The depths of the steps are simply continuous parameters and the deviations in the predicted physical properties comprise the objective function. The selection of optimal step widths necessitates a degree of integer programming. The optimization of site diameter carries a significant penalty in requiring a fresh simulation. Developing a strategy for global optimization of this system presents a novel challenge for optimization methodology. Although DMD/TPT is particularly well suited to this kind of optimization at this time, it is also possible through derivative and histogram reweighting methods to probe the sensitivity of physical properties to parameters in continuous potentials. As researchers using continuous potentials make progress, they will come to see the need for a reliable and efficient methodology for optimizing transferable potential parameters.Broader Impacts: These will include integrated research and education and international exchange. The PI is the co-author of a text on Chemical Engineering Thermodynamics, and has already integrated results of related previous NSF support, and his teaching should evolve to include product design requiring extensive molecular insight. It is anticipated that there will be progressively greater importance for chemical product design in the curriculum. This collaboration will demonstrate a paradigm for international research that substantially leverages the interests and capabilities in both sides.