Development of a General, Fully Relativistic, Parallelized B-Spline R-Matrix with Pseudo-States Program for Electron and Photon Interactions with Atoms, Ions, and Molecules

该项目的目的是进一步开发一个通用的和有效的，完全相对论性的计算机代码，用于电子和光子与原子，离子和分子的相互作用，使用B样条R矩阵（BSR）方法。 这种创新的方法具有显着的优势，在标准套件的R-矩阵码，主要是在过去的四十年中开发的贝尔法斯特和目前使用的世界各地。 具体而言，B样条基的优良数值特性允许高计算精度，并且采用非正交项依赖轨道集的能力允许紧凑的构型扩展。 在目前的资助期间，现有的计算机代码将完全并行化，并将开发一套新的通用原子结构代码，该代码直接使用B样条作为BSR碰撞代码的改进接口。 此外，一个并行的B样条代码，以解决在外部区域的紧耦合方程，和一个试点版本的BSR程序处理时间依赖的过程，如强烈的短脉冲XUV激光原子相互作用，将扩展到双电离和红外辐射。 最后，潜在的使用的BSR方法来描述电子和光子与双原子分子的相互作用将investigated.The更广泛的影响，该项目包括一个非常成功的计算机程序套件的进一步发展，以计算各种各样的电子和光子驱动的过程的准确的原子数据。 生产计算将集中在原子目标上，这些数据对于模拟天体物理和实验室等离子体，激光和行星大气的物理和化学具有关键价值。 这项工作将支持许多实验项目，从工业照明系统到下一代同步加速器和自由电子激光器的基础研究。 研究结果将在国际科学会议上公布，下一个版本的计算机代码将被编写出来并向公众提供。 最后，本科生将通过开发和测试该软件包的各个模块进行培训。 这包括在通过XSEDE资源提供的大规模并行计算平台上运行代码。

The purpose of this project is to further develop a general and effective, fully relativistic computer code for electron and photon interactions with atoms, ions, and molecules using the B-spline R-matrix (BSR) method. This innovative approach has significant advantages over the standard suite of R-matrix codes, mostly developed over the past four decades in Belfast and currently used worldwide. Specifically, the excellent numerical properties of a B-spline basis allow for high computational accuracy, and the ability to employ non-orthogonal sets of term-dependent orbitals allows for compact configuration expansions. During the current funding period, the existing computer code will be fully parallelized, and a new suite of general atomic structure codes will be developed, which directly use the B-spline as an improved interface to the BSR collision codes. Furthermore, a parallelized B-spline code to solve the close-coupling equations in the outer region will be developed, and a pilot version of the BSR program to treat time-dependent processes, such as intense short-pulse XUV laser-atom interactions, will be extended to double ionization and infrared radiation. Finally, the potential use of the BSR method to describe electron and photon interactions with diatomic molecules will be investigated.The broader impact of the project consists of the further development of a highly successful suite of computer programs to calculate accurate atomic data for a wide variety of electron- and photon-driven processes. The production calculations will focus on atomic targets, for which these data are of critical value to model the physics and chemistry of astrophysical and laboratory plasmas, lasers, and planetary atmospheres. This work will support many experimental projects ranging from industrial lighting systems to fundamental research performed at next-generation synchrotrons and free-electron lasers. The results will be presented at international scientific meetings, and the next version of the computer code will be written up and made available to the public. Finally, undergraduate students will be trained through developing and testing individual modules of the package. This includes running the code on massively parallel computing platforms provided through XSEDE resources.