Accurate atomic quantum defects from particle-particle random phase approximation

Journal Article (Journal Article)

The accuracy of calculations of atomic Rydberg excitations cannot be judged by the usual measures, such as mean unsigned errors of many transitions. We show how to use quantum defect (QD) theory to (a) separate errors due to approximate ionisation potentials, (b) extract smooth QDs to compare with experiment, and (c) quantify those defects with a few characteristic parameters. The particle-particle random phase approximation (pp-RPA) produces excellent Rydberg transitions that are an order of magnitude more accurate than those of time-dependent density functional theory with standard approximations. We even extract reasonably accurate defects from the lithium Rydberg series, despite the reference being open-shell. Our methodology can be applied to any Rydberg series of excitations with four transitions or more to extract the underlying threshold energy and characteristic QD parameters. Our pp-RPA results set a demanding challenge for other excitation methods to match.

Full Text

Duke Authors

Cited Authors

  • Yang, Y; Burke, K; Yang, W

Published Date

  • April 17, 2016

Published In

Volume / Issue

  • 114 / 7-8

Start / End Page

  • 1189 - 1198

Electronic International Standard Serial Number (EISSN)

  • 1362-3028

International Standard Serial Number (ISSN)

  • 0026-8976

Digital Object Identifier (DOI)

  • 10.1080/00268976.2015.1123316

Citation Source

  • Scopus