Theorectical Studies of van der Waals Molecules

范德华分子的理论研究

• 批准号: 9626739
• 负责人: Krzysztof Szalewicz
• 金额: $ 32.07万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-01 至 1999-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9626739&HistoricalAwards=false
• 关键词: Theorectical; Studies; van; der; Waals

This project, supported by the NSF Theoretical and Computational Chemistry Program, investigates the phenomenon of intermolecular interactions. Prof. Krzysztof Szalewicz of the University of Delaware and collaborators will further improve symmetry-adapted perturbation theory (SAPT) developed by them for dimer interactions, and a new version applicable to trimers will be derived. This theory allows transparent physical interpretation of intermolecular potentials in terms of four fundamental interactions: electrostatic, exchange, induction, and dispersion. The theory is free from basis set superposition problems and is computationally more efficient than the supermolecular many-body perturbation theory approach. High-level calculations of state-of-the-art intermolecular potential energy surfaces for experimentally relevant van der Waals dimers and trimers will be performed. These studies will help provide an understanding of the real physical mechanism for the formation of van der Waals bonds and the physical interactions that are responsible for minima, tunneling barriers, and anisotropies of the potentials. This work is expected to assist interpretation of experimental data, particularly in the case of three-body nonadditivities. An important part of the project will involve applications aimed at resolving current problems in the field concerning interactions of rare gas atoms with various molecules such as nitrogen, carbon dioxide, water, or ammonia, as well as dimers of those molecules. The trimers will include rare gas atoms, Ar2-HF, and the water trimer. The current theoretical understanding of three-body interactions is very unsatisfactory, in particular in view of recent experimental activity in this field. The SAPT method offers the possibility of physical analysis of nonadditivities and of obtaining accurate numerical values for them. This project investigates the phenomenon of interactions between molecules. These interactions, much weaker than the chemical forces binding atoms in molecules, are responsible for an extensive range of physical, chemical, and biological phenomena: from the boiling of water to the genetic code. Standard computational chemistry methods, which are very successful in describing chemical bonds, are inadequate in describing these intermolecular forces. Szalewicz and collaborators will develop and use rigorous methods based on a quantum mechanical description of these systems in order to provide a more complete understanding of these molecular interactions.

在NSF理论和计算化学计划的支持下，该项目研究了分子间相互作用的现象。 特拉华大学的Krzysztof Szalewicz教授和合作者将进一步改善由他们为二聚体交互开发的对称性适应的扰动理论（SAPT），并将得出适用于三聚机的新版本。 该理论允许根据四个基本相互作用：静电，交换，诱导和分散对分子间电位的透明物理解释。 该理论没有基础设置的叠加问题，并且在计算上比超分子多体扰动理论方法更有效。 将对实验相关的范德华二聚体和三聚体进行最新的分子间势能表面的高级计算。 这些研究将有助于了解范德华键形成的实际物理机制以及负责极小，隧道障碍和潜力各向异性的物理相互作用。 预计这项工作将有助于解释实验数据，特别是在三体非目标的情况下。 该项目的一个重要部分将涉及旨在解决稀有气体原子与氮，二氧化碳，水或氨的各种分子的相互作用以及这些分子二聚体等各种分子的相互作用的应用。 三聚体将包括稀有气体原子，AR2-HF和水三聚体。当前对三体相互作用的理论理解非常不令人满意，特别是鉴于该领域的最新实验活动。 SAPT方法提供了对非目标的物理分析的可能性，并为其获得准确的数值。 该项目研究了分子之间相互作用的现象。 这些相互作用比分子中的化学力结合原子弱得多，是造成广泛的物理，化学和生物学现象的范围：从水的沸腾到遗传密码。 描述化学键非常成功的标准计算化学方法在描述这些分子间力时不足。 Szalewicz和合作者将根据这些系统的量子机械描述来开发和使用严格的方法，以便对这些分子相互作用有更完整的了解。