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.

佐治亚大学的亨利（Fritz）Schaefer得到了化学理论，模型和计算方法计划的奖项，以及计算和基于数据支持的科学与工程计划（CDS＆E），以开发新的量子化学方法，以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。 非常小的颗粒，例如电子，遵循量子力学定律。 因此，量子化学或电子结构方法对于对化学反应以及其他重要的原子和分子过程的基本了解至关重要。 量子力学的基本方程式（施罗丁格方程）在计算机上求解。 除最小分子以外的所有分子以外的所有量子机械描述将需要大量的计算机时间。 量子化学家的目标是开发更有效，更准确的方法。 Schaefer和他的同事开发了称为密度累积理论的重要新方法。 （DCT）该研究项目具有两个不同但相关的目的。首先是DCT方法的假设，公式，开发，实施和测试。其次，这些新技术用于解决重要的原型化学问题。这些方法是在称为PSI4的公开可用的，用户友好的量子化学软件包中实现的。 PSI4目前的许多开发人员目前都是Schaefer研究小组的成员。 在Schaefer实验室中，正在开发一种重要的新方法，密度累积理论（DCT）。 更具体地追求的是（1）单一转换分析中的N-代表性条件； （2）从两粒子密度矩阵的势力中的n-明显性； （3）使用不可约定的施罗辛格方程的替代DCT层次结构； （4）DCT中的三电子相关效应； （5）使用成对的天然轨道进行大规模化学应用的有效DCT实施。 还解决了非常大的分子系统的线性缩放算法。正在开发和分发用于电子结构理论的下一代计算机程序的免费开源PSI4套件。 从物理和材料到无机，有机和生物化学的应用程序已通过最新的理论方法成功完成。