Multi-Configuration Pair-Density Functional Theory

通过这一奖项，化学系的化学理论、模型和计算方法计划支持明尼苏达大学的劳拉·加利亚迪教授和唐纳德·G·特鲁拉教授开发理论方法和工具来描述非常重要的一类分子的电子结构，这些分子很难用最广泛使用的现有方法进行研究。特别是，密度泛函理论(DFT)方法已经成为现代量子力学方法研究大分子和复杂分子体系的主力。这项计划中的研究结合了加利亚迪和特鲁拉尔研究小组的特殊专业知识，以开发一种方法，利用他们各自研究的各个方面。作为这项研究的一部分，开发的技术将适用于预计将在以下应用领域产生广泛影响的分子体系：化学动力学、热化学、环境化学，包括大气化学和水环境、电化学、催化、材料、超分子化学、生物化学和纳米技术。因此，这项工作将对健康、材料、环境和工业应用产生长期影响。作为这项研究的一个组成部分，本科生、研究生和博士后研究员将接受现代计算化学方法的培训。在该项目中开发的软件以可移植的、有详细记录的代码免费分发给社区。在这个奖项下，Gagliardi和Truhlar研究小组正在开发和实施一种新的量子化学理论，称为多组态对密度泛函理论(MC-PDFT)。该项目将探索将密度泛函理论与多参照系的多组态波函数相结合的新方法。MC-PDFT保持了所考虑系统的正确自旋和空间对称性，同时避免了重复计算电子关联能的任何可能性。MC-PDFT计算成本的扩展被认为是有希望的。该方法用于化学性质的测定，如键能和电子激发能，以及用于光化学应用的势能面的生成。

With this award, the Chemical Theory, Models and Computational Methods Program in the Chemistry Division is supporting Professors Laura Gagliardi and Donald G. Truhlar of the University of Minnesota to develop theoretical methods and tools to describe the electronic structure of very important classes of molecules that are difficult to study by most widely used, established approaches. In particular, density functional theory (DFT) methods have become the "workhorse" of modern quantum mechanical methods for large and complex molecular systems. The planned research combines the particular expertise of the Gagliardi and Truhlar research gruops to develop a method that draws on aspects of each of their individual research. The techniques developed as part of this research will be applicable to molecular systems that are expected to have broad impacts in, among others, the following application areas: chemical dynamics, thermochemistry, environmental chemistry, including atmospheric chemistry and aqueous environments, electrochemistry, catalysis, materials, supramolecular chemistry, biochemistry, and nanotechnology. Thus the work is poised to have long-term implications for health, materials, environmental, and industrial applications. Undergraduates, graduate students and postdoctoral fellows will be trained in modern computational chemistry methods as an integral part of this research. Software developed in the project is distributed free to the community in portable well-documented code.Under this award, the Gagliardi and Truhlar research groups are developing and implementing a new quantum chemical theory, called multiconfiguration pair-density functional theory (MC-PDFT). The project will explore new ways to combine density functional theory with multiconfiguration wave functions for multireference systems. MC-PDFT maintains the correct spin and spatial symmetry of the systems under consideration and, at the same time, avoids any possibility of double counting the electron correlation energy. The scaling of the computational costs of MC-PDFT is seen to hold promise. The method is employed for the determination of chemical properties such as bond energies and electronic excitation energies and for the generation of potential energy surfaces to be used in photochemical applications.