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

对原子和分子结构以及碰撞的定量理解是理论原子和分子物理学研究的主要领域之一。 从这个研究领域的结果形成关键输入到基础理论和实验研究在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。此外，这项研究与具有重要社会意义的重要实际应用有关，例如为GPS系统开发更好的时钟。迄今为止，这一领域的成功主要局限于对较简单原子系统的研究;对周期表中更复杂原子的理解还没有达到可比水平。 该项目的重点是开发一种高精度的理论和计算方法，旨在将过渡金属复杂原子的理论理解提高到目前仅提供给更简单原子系统的复杂程度。 如果成功的话，这些结果将为元素周期表的许多应用打开大门，而这些应用迄今为止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分的机会，培训他们研究物理学科学研究的前沿课题。该项目旨在开发下一代完全相对论性的广泛适用的原子代码，基于大尺度组态相互作用和全阶线性耦合团簇方法的组合，能够以百分之几的精度预测开壳层原子的性质。该代码的主要特点是能够处理系统中没有准确的描述原子属性是目前可能的。虽然最近在高精度原子计算方面取得了巨大进展，但在d-和f-壳层开放系统中处理相关性对AMO理论提出了前沿挑战。这个项目将解决以下短期的当前的方法需要在d-和f-壳层原子开放系统的相关性的治疗：省略三体相互作用，有限的选择的启动潜力，并需要有效地选择最重要的配置非常大的配置空间的建设。由此产生的代码将能够计算范围广泛的原子性质，包括能量，g因子，超精细常数，各种过渡矩阵元素，电偶极子和电四极静态和动态极化率，长程相互作用势参数，各种P（奇偶）奇和T（时间）奇效应，灵敏度因子的精细结构常数的变化测试和局部洛伦兹不变性的原子测试。新一代代码的性能将在具有多个价电子的系统中进行测试。

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.