Development and Application of Nonempirical Density-Functional Methods

斯塔沃夫教授的团队开发了电子结构理论，这是量子科学的一个分支，用于了解化学键和预测化学反应的结果。他专门研究被称为密度泛函理论(DFT)的方法，在探索KohnSham有效势方面拥有全球公认的领导地位，KohnSham有效势是DFT的基本成分。 由于DFT方法必须依赖于未知交换相关泛函的不完全近似，所以DFT的作用还没有完全实现。这一建议的首要目标是通过探索计算精确KohnSham势和近似交换关联泛函的极具原创性的新方法来提高DFT的能力。短期目标分为三个相互关联的主题。 计算方法。所有实用的DFT计算都使用基集，但KohnSham有效势是通过推导出的公式计算的，就像根本不存在基集一样，这导致了令人困惑的不一致。为了解决这个问题，我们将开发一种史无前例的方法来构建在所有情况下都能正常工作的交换关联势。我们还将设计一个从有限基组密度计算交换关联势的数值上更优越的程序，这将成为计算材料研究中使用的密度嵌入方案的一部分。最后，我们将探索一个新的想法，使密度泛函近似正确地适用于具有伸展键的分子，这将极大地扩展现有密度泛函在计算催化中的能力。 理论框架。我们将开始系统地探索一种计算有限基集上的有效势的新方法，以消除用于该目的的现有方法的模糊性。我们还将通过推导数学测试来推进有效势理论，这将使DFT研究人员能够判断他们的模型对于计算有限基组中的分子性质是否具有物理意义。 化学应用。我们将解决功能材料化学中的两个难题：甲酸硼染料的基态和电子激发态之间的本质区别是什么，可以解释这些分子的异常光学性质？为什么传统的密度泛函不能描述结晶的氢化硼？对这些问题的回答将指导实验化学家制造高效的能量转换材料，并将开辟改进密度泛函的新方法。 这项研究的结果将对成千上万的科学家来说很重要，他们以软件包的形式使用DFT来解决理论、有机、无机和材料化学中的问题。斯塔沃洛夫教授的受训人员将获得一套特殊的技术和专业技能，以及为他们在科学和技术领域具有高度影响力的职业生涯做准备的成才经验。

Prof. Staroverov's group develops electronic structure theorya branch of quantum science used to understand chemical bonding and predict outcomes of chemical reactions. He specializes in the approach called density-functional theory (DFT) and holds a globally recognized leadership position in the exploration of KohnSham effective potentials, the fundamental ingredients of DFT. The power of DFT is not yet fully realized because this method has to rely on imperfect approximations to the unknown exchange-correlation functional. The overriding goal of this proposal is to advance the capabilities of DFT by exploring highly original new ways of computing exact KohnSham potentials and approximating the exchange-correlation functional. The short-term objectives fall within three interrelated themes. Computational methods. All practical DFT calculations use basis sets, but KohnSham effective potentials are computed by formulas derived as if basis sets never existed, which leads to confusing inconsistencies. To address this issue, we will develop an unprecedented method for constructing exchange-correlation potentials that works properly in all situations. We will also devise a numerically superior procedure for computing exchange-correlation potentials from finite-basis-set densities, which will become part of density-embedding schemes used in computational materials research. Finally, we will explore a novel idea to make density-functional approximations work correctly for molecules with stretched bonds, which will drastically expand the power of existing density functionals in computational catalysis. Theoretical framework. We will initiate a systematic exploration of a new way to compute effective potentials in finite basis sets in order to eliminate the ambiguities of existing methods used for that purpose. We will also advance the theory of effective potentials by deriving mathematical tests which will enable DFT researchers to tell whether their models are physically sensible for calculating molecular properties in finite basis sets. Chemical applications. We will tackle two puzzles in the chemistry of functional materials: What are the essential differences between the ground and electronically excited states of boron-formazanate dyes that can explain the unusual optical properties of these molecules? Why do conventional density functionals fail for describing crystalline boron hydrides? Answers to these questions will guide experimental chemists making efficient energy conversion materials and will open up new ways of improving DFT. The outcomes of this research will be important to thousands of scientists who use DFT in the form of software packages to solve problems in theoretical, organic, inorganic, and materials chemistry. Prof. Staroverov's trainees will gain an exceptional set of technical and professional skills, and a formative experience preparing them for highly impactful careers in science and technology.