- Date: September 26th, 2018
- Time: 10:00AM-12:00PM
- Location: 116 Pearson Hall, Faculty Commons
Development of a relativistic atomic code for accurate treatment of complex correlations
Presenter: Marianna Safronova
Other authors: C. Cheung, M. G. Kozlov, S. G. Porsev, and I. I. Tupitsyn
National Science Foundation Workshop on Atomic, Molecular and Optical (AMO) Theory identified “describing complex correlations in atomic-molecular structure and collisions” as a one of the central objective of AMO physics in the coming decade, due to its fundamental importance and relevance to new experiments. The need for the practical solution to the accurate calculation of atomic properties or systems in the middle columns of the periodic table became even more urgent due to a number of experimental applications to subjects such as time-dependence of the fundamental constants, studies of fundamental interactions, atomic clock research, dark matter searches, analysis of astrophysical data, plasma science, studies of quantum degenerate gases and production of ultracold molecules, and quantum information. The goal of our project is to continue development of a broadly applicable atomic code for predicting properties of open d- and f-shell atoms to good precision. This code is based on the combination of configuration interaction (CI) and many-body perturbation theory (CI+MBPT) or all-order linearized coupled-cluster methods. One of the main difficulties is the exponential scaling of the number of CI configurations with the number of the valence electrons. We describe the new algorithms for sub-selecting important configurations and challenges in the MPI parallelization of the code. A version of the CI+MBPT code was documented and made available for the scientific community [1]. [1] M. G. Kozlov, S. G. Porsev, M. S. Safronova, and I. I. Tupitsyn, Computer Physics Communications 195, 199 (2015).