Development of High-Quality Models for Anhydrous and Aqueous Hydrogen Fluoride

无水和含水氟化氢的高质量模型的开发

• 批准号: 0076515
• 负责人: David Kofke
• 金额: $ 17万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-15 至 2003-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0076515&HistoricalAwards=false
• 关键词: Development; Quality; Models; Anhydrous; Aqueous

ABSTRACTCTS-0076515Kofke, D. A.SUNY @ BuffaloThis project is concerned with the development of models that can predict and characterize a broad range of properties of hydrogen fluoride (HF) and its mixtures with water. The specific aim of the project is to develop and test molecular models appropriate for these systems. The larger aim in all of this work is the advancement of modeling techniques that bridge ab initio quantum chemistry and bulk-phase modeling via molecular simulation. Thus the specific focus of the project provides a vehicle for treating a problem of much broader impact.The modeling incorporates as much as possible the fundamental quantum chemistry that governs the molecular interactions. Several approaches are examined. The first approach adopts methods that are currently in wide used for quantitative modeling. Dispersion and repulsive interaction are treated with 12-6 exp-6 models, and hydrogen-bonding is modeled via a simple electrostatic treatment (e.g., point charges). It is anticipated that this methodology will fail because it does not capture important features of HF interactions. Other approaches are considered to include the quantum-mechanical effects present in HF that are difficult to capture using an analytic potential. These include a combined quantum- and molecular-mechanics treatment that ahs been applied to water, and a treatment that considers three-body effects explicitly coupled with a high-quality model for the dimer. Advances in modeling of HF are then introduced to molecular models of water to examine the behavior of HF/water mixtures. It is of interest to test the validity of any HF/water model by examining its ability to explain the thermodynamic inconsistency obtained in the application of simple models to published experimental HF/water vapor-liquid equilibrium data.All modeling efforts here are concerned with the volumetric properties, phase equilibria and heat effects. The behavior of HF in all of these directions is highly anomalous. Additional components of this study are concerned with the effect of intermolecular association on surface tension, and on the development of improved molecular simulation techniques of associating fluids. The interest in the former is driven by the anomalously small surface tension of HF, which contributes to its ability to form aerosols (a significant safety problem), while the motivation for the latter is related to the natural inefficiency of simulation when applied to associating systems, combined with our interest in studying such systems with computationally expensive molecular models.

Abstractcts-0076515Kofke，D。A。Suny @ Buffalothis项目与可以预测和表征氟化氢（HF）及其与水混合的模型的发展有关。 该项目的具体目的是开发和测试适合这些系统的分子模型。 在所有这项工作中，更大的目的是建模技术的发展，该技术通过分子模拟桥接了量子化学和散装期建模。 因此，该项目的具体重点为处理更广泛影响的问题提供了一种工具。建模尽可能多地结合了控制分子相互作用的基本量子化学。 检查了几种方法。 第一种方法采用了当前用于定量建模的方法。 分散和排斥性相互作用用12-6个EXP-6模型处理，并通过简单的静电处理（例如，点电荷）对氢键进行建模。 可以预料，该方法将失败，因为它不会捕获HF交互的重要特征。 其他方法被认为包括HF中存在的量子力学效应，这些量子很难使用分析潜力捕获。 其中包括将AHS应用于水的量子和分子力学处理，以及一种考虑三体效应与二聚体高质量模型明确耦合的治疗方法。 然后将HF建模的进展引入水分子模型，以检查HF/水混合物的行为。 通过研究其解释在将简单模型应用于发布的实验性HF/水蒸气 - 液体平衡数据时获得的热力学不一致的能力来测试任何HF/水模型的有效性，这是有趣的。体积特性，相位平衡和热效应。 HF在所有这些方向上的行为是高度异常的。 这项研究的其他组成部分涉及分子间关联对表面张力的影响，以及改善关联流体的分子模拟技术的发展。 对前者的兴趣是由HF的异常表面张力驱动的，HF的表面张力有助于形成气溶胶的能力（这是一个重大的安全问题），而后者的动机与应用于关联系统的模拟自然效率低下有关加上我们对使用计算昂贵的分子模型研究此类系统的兴趣。