{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/homogeneous-electron-gases-revisited-through","title":"Local density approximation for excited states","arxiv_id":"2306.04023","date":"2023-06-06","proceeding":null,"authors":["Tim Gould","Stefano Pittalis"],"abstract":"The ground state of an homogeneous electron gas is a paradigmatic state that has been used to model and predict the electronic structure of matter at equilibrium for nearly a century. For half a century, it has been successfully used to predict ground states of quantum systems via the local density approximation (LDA) of density functional theory (DFT); and systematic improvements in the form of generalized gradient approximations and evolution thereon. Here, we introduce the LDA for \\emph{excited} states by considering a particular class of non-thermal ensemble states of the homogeneous electron gas. These states find sound foundation and application in ensemble-DFT -- a generalization of DFT that can deal with ground and excited states on equal footing. The ensemble-LDA is shown to successfully predict difficult low-lying excitations in atoms and molecules for which approximations based on local spin density approximation (LSDA) and time-dependent-LDA fail.","url_abs":"https://arxiv.org/abs/2306.04023v4","url_pdf":"https://arxiv.org/pdf/2306.04023v4.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"homogeneous-electron-gases-revisited-through","repo_url":"https://github.com/gambort/cofheg","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}