Development of a General and Effective Program B-Spline R-Matrix program for Charged-Particle and Photon Collisions with Atoms, Ions, and Molecules

Drake University, Des Moines IA

Investigators

Abstract

The purpose of this project is to continue the development of a fully relativistic computer code for electron and photon interactions with atoms and ions. The code has already been employed in a number of benchmark calculations to obtain highly accurate atomic data of critical importance for fundamental research and practical applications. In particular, the code is being used to model the physics and chemistry of astrophysical and laboratory plasmas, lasers, and planetary atmospheres. The computer code will be made available to the general public through an open-source license and a designated website. Undergraduate students will be trained in modern computational methods through developing and testing individual modules of the package. This includes running the code on massively parallel computing platforms provided through the eXtreme Science and Engineering Discovery Environment (XSEDE) resources supported by the National Science Foundation. The B-spline R-matrix (BSR) approach has significant advantages over the well-known suite of R-matrix (close-coupling) codes that were developed over the past four decades and are currently used worldwide. Specifically, the numerical properties of a B-spline basis yield high computational accuracy and the ability to employ non-orthogonal sets of term-dependent orbitals allows for compact configuration expansions. After having completed the parallelization of the semi-relativistic version, this project will support the development of a parallel implementation of the fully relativistic Dirac-Coulomb version. The BSR collision codes will also be interfaced with a new suite of general atomic structure codes, which use B-spline expansions directly.