Development of Next-Generation Relativistic Program for All-Order Treatment of Many-Electron Systems

开发用于多电子系统全序处理的下一代相对论程序

• 批准号: 1620687
• 负责人: Marianna Safronova
• 金额: $ 42万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1620687&HistoricalAwards=false
• 关键词: Development; Next; Generation; Relativistic; Program

The quantitative understanding of atomic and molecular structure and collisions represents one of the main areas of research in theoretical atomic and molecular physics. Results from this area of research form key input to fundamental theoretical and experimental studies in a broad range of basic and applied scientific fields, including astrophysics, plasma science, and quantum information. In addition, this research is relevant for important practical applications with important societal implications, such as the development of better clocks for GPS systems. To date success in this area has been primarily restricted to studies of the simpler atomic systems; comparable levels of understanding have not been achieved for more complex atoms in the Periodic Table. This project focuses on developing a high-precision theoretical and computational approach that seeks to bring the theoretical understanding of complicated atoms of transition metals to the same level of sophistication afforded presently only to much simpler atomic systems. If successful, the results could open up much of the Periodic Table to applications that heretofore could only be pursued with the simplest atoms. As such, this project provides ample opportunities for the training of students and post-doctoral fellows on topics at the leading edge of scientific research in physics. This project aims to develop a next-generation fully relativistic broadly applicable atomic code, based on the combination of large-scale configuration interaction and all-order linearized coupled-cluster method capable of predicting properties of open-shell atoms with precision of a few percent. The main feature of the code is to be able to treat systems where no accurate description of atomic properties is presently possible. While tremendous progress has been made recently in high-precision atomic calculations, treatment of correlation in d- and f-shell open systems present frontier challenges to AMO theory. This project will address the following short comings of current approaches needed for the treatment of correlations in d- and f-shell atomic open systems: omission of three-body interactions, limited choice of the starting potential, and the need for efficient selection of most important configurations for the construction of very large configuration spaces. The resulting code will be able to calculate a wide range of atomic properties including energies, g-factors, hyperfine constants, various transition matrix elements, electric-dipole and electric-quadrupole static and dynamic polarizabilities, long-range interaction potential parameters, various P(parity)-odd and T(time)-odd effects, sensitivity factors for tests of variation of the fine-structure constant and atomic tests of local Lorentz invariance. The performance of the new-generation code will be tested for systems with several valence electrons.

对原子和分子结构及碰撞的定量理解是理论原子和分子物理学的主要研究领域之一。 该研究领域的成果为广泛的基础和应用科学领域（包括天体物理学、等离子体科学和量子信息）的基础理论和实验研究提供了关键投入。此外，这项研究还与具有重要社会影响的重要实际应用相关，例如为 GPS 系统开发更好的时钟。迄今为止，该领域的成功主要局限于对较简单原子系统的研究。对于元素周期表中更复杂的原子尚未达到相当水平的理解。 该项目的重点是开发一种高精度的理论和计算方法，旨在将对复杂过渡金属原子的理论理解达到目前仅适用于更简单的原子系统的相同复杂水平。 如果成功的话，这些结果可能会为元素周期表中的大部分内容开辟新的应用领域，而此前这些应用只能用最简单的原子来实现。因此，该项目为学生和博士后研究员提供了充足的机会来培训物理学科学研究前沿的课题。该项目旨在开发下一代完全相对论广泛适用的原子代码，基于大规模构型相互作用和全阶线性化耦合团簇方法的结合，能够以百分之几的精度预测开壳原子的性质。该代码的主要特点是能够处理目前无法准确描述原子属性的系统。尽管最近在高精度原子计算方面取得了巨大进展，但 d 壳层和 f 壳层开放系统中相关性的处理对 AMO 理论提出了前沿挑战。该项目将解决当前处理 d 和 f 壳层原子开放系统相关性所需的方法的以下缺点：三体相互作用的省略、起始势的选择有限以及需要有效选择大多数构建非常大的配置空间的重要配置。生成的代码将能够计算各种原子属性，包括能量、g 因子、超精细常数、各种过渡矩阵元素、电偶极子和电四极子静态和动态极化率、长程相互作用势参数、各种 P （宇称）奇效应和 T（时间）奇效应、精细结构常数变化测试的敏感因子和局部洛伦兹不变性的原子测试。新一代代码的性能将针对具有多个价电子的系统进行测试。