Molecular Electronic Structure Theory: Methods and Applications

分子电子结构理论：方法与应用

• 批准号: 1361178
• 负责人: Henry Schaefer III
• 金额: $ 43.18万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1361178&HistoricalAwards=false
• 关键词: Molecular; Electronic; Structure; Theory; Methods

Henry (Fritz) Schaefer of the University of Georgia is supported by an award from the Chemical Theory, Models and Computational Methods Program in the Chemistry Division and the Computational and Data-Enabled Science and Engineering Program (CDS&E) to develop new quantum chemistry methods to study the behavior of electrons in molecules. The electrons in atoms and molecules are responsible for making and breaking chemical bonds. Very small particles, such as electrons, follow the laws of quantum mechanics. Thus, quantum chemistry or electronic structure methods are essential for a fundamental understanding of chemical reactions as well as other important atomic and molecular processes. The basic equation of quantum mechanics, the Schroedinger equation, is solved on a computer. An exact quantum mechanical description of all but the smallest molecules would require vast amounts of computer time. A goal of quantum chemists is to develop more efficient and more accurate methods. Schaefer and his co-workers have developed important new methods called Density Cumulant Theory. (DCT) This research project has two, distinct but related aims. The first is the hypothesis, formulation, development, implementation, and testing of the DCT method. Second, these new techniques are used to solve important prototypical chemical problems. These methods are implemented in a publicly available, user-friendly quantum chemistry software package called PSI4. Many of the current developers of PSI4 are currently members of Schaefer's research group. In the Schaefer laboratory, an important new method is being developed, Density Cumulant Theory (DCT). More specifically being pursued are (1) N-representability conditions from analyses of unitary transformations; (2) N-representability from the idempotency of the two-particle density matrix; (3) alternative DCT hierarchies using the irreducible contracted Schroedinger equation; (4) three-electron correlation effects in DCT; and (5) efficient DCT implementations using pair natural orbitals for large scale chemical applications. Also being tackled are linear-scaling algorithms for very large molecular systems. The freely available, open-source PSI4 suite of next generation computer programs for electronic structure theory is being developed and distributed. Applications ranging from physical and materials to inorganic, organic and biological chemistry are successfully being completed with state-of-the-art theoretical methods.

格鲁吉亚大学的亨利（弗里茨）谢弗得到了化学系化学理论，模型和计算方法项目以及计算和数据支持科学与工程项目（CDS E）的支持，以开发新的量子化学方法来研究分子中电子的行为。 原子和分子中的电子负责建立和破坏化学键。 非常小的粒子，如电子，遵循量子力学定律。 因此，量子化学或电子结构方法对于化学反应以及其他重要的原子和分子过程的基本理解至关重要。 量子力学的基本方程，薛定谔方程，在计算机上求解。 除了最小的分子之外，所有分子的精确量子力学描述都需要大量的计算机时间。 量子化学家的目标是开发更有效和更准确的方法。 Schaefer和他的同事开发了重要的新方法，称为密度累积理论。 (DCT)这个研究项目有两个不同但相关的目标。首先是假设，制定，发展，实施和测试的DCT方法。其次，这些新技术被用来解决重要的原型化学问题。这些方法在一个公开的、用户友好的量子化学软件包PSI 4中实现。目前PSI 4的许多开发人员都是Schaefer研究小组的成员。 在Schaefer实验室，一个重要的新方法正在开发中，密度累积理论（DCT）。 更具体地说，正在追求的是（1）从酉变换分析的N-可表示性条件;（2）从两粒子密度矩阵的幂等性的N-可表示性;（3）使用不可约的收缩薛定谔方程的替代DCT层次;（4）DCT中的三电子相关效应;和（5）使用对自然轨道的有效DCT实现大规模化学应用。 也正在处理的是非常大的分子系统的线性尺度算法。免费提供的，开源的PSI 4套件的下一代计算机程序的电子结构理论正在开发和分发。 从物理和材料到无机，有机和生物化学的应用都是通过最先进的理论方法成功完成的。