Modeling of London Dispersion Interactions in Molecular Chemistry

对伦敦色散相互作用的准确描述及其用现代量子化学方法进行的‘化学’分析是这个项目的中心主题。基于我们对色散校正平均场(DFT-D/NL)方法的洞察和经验，我们将继续通过三个领域的项目为透彻理解和量化分子体系中的伦敦色散相互作用做出贡献：方法开发、在理论上困难或非标准情况下与其他参与者的联合应用和支持。具体来说，将考虑以下主题：-通过基于稳健和准确的紧束缚量子化学方法和新的分子间力场的新的、单独开发的复合过程来自动生成即使对于大系统的构象系综和团簇结构，-溶液中的分子热化学和反应势垒和机制的计算，重点是分散控制，-非共价相互作用的能量分解分析，以揭示分散的重要性，特别是关于分散能量供体(DED)和反DED(去稳定)行为，-进一步发展包括多体色散效应的D4模型--非局部VV10密度泛函与激发态量子化学方法的耦合，以及对涉及电子激发的实验的解释。特别关注色散对感兴趣的化学性质的影响。对于所应用的色散校正密度泛函方法，这在技术上和概念上都是容易实现的，因为假定电子能量和色散能量是相加的，并且可以很容易地开启/关闭校正。此外，所提出的D4模型(与D3模型相比)将允许研究色散效应的电荷依赖关系，特别是对于金属系统，以及更准确地考虑多体色散能量。新的DFT-D4方法具有更高的精确度，结合改进的抽样技术，将导致总体上显着提高治疗的可靠性。

The accurate account of London dispersion interactions and their 'chemical' analysis by modern quantum chemical methods are the central themes of this project. Based on our insight and experience with dispersion corrected mean-field (DFT-D/NL) methods we will continue to contribute to gaining a thorough understanding and quantification of London dispersion interactions in molecular systems with projects in the three areas: method development, joint applications with and support of other participants in theoretically difficult or non standard cases. In detail, the following topics will be considered:- automatic generation of conformation ensembles and cluster structures even for large systems by a new, separately developed composite procedure based on a robust and accurate tight-binding quantum chemical method and the new intermolecular force field,- molecular thermochemistry in solution and computation of reaction barriers and mechanisms with an emphasis on dispersion control,- energy decomposition analysis of non-covalent interactions to reveal the importance of dispersion in particular regarding dispersion energy donor (DED) vs. anti-DED (de-stabilising) behavior,- further development of the D4 model including many-body dispersion effects- coupling of the non-local VV10 density functional with excited state quantum chemistry methods and interpretation of experiments involving electronic excitationParticular attention will be paid to the effect of dispersion on the chemical property of interest. With the applied dispersion corrected density functional methods this is technically and conceptually easily possible because the electronic and dispersion energies are assumed to be additive and the correction can easily be switched on/off. In addition the proposed D4 model (in comparison to D3) will allow to investigate the charge dependence of dispersion effects in particular for metallic systems as well as a more accurate consideration of the many-body dispersion energy. The higher accuracy of the new DFT-D4 methods in combination with improved sampling techniques will lead to overall significantly increased reliability of the treatments.