{"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/qsym-2-a-quantum-symbolic-symmetry-analysis","title":"QSym$^2$: A Quantum Symbolic Symmetry Analysis Program for Electronic Structure","arxiv_id":"2310.06749","date":"2023-10-10","proceeding":null,"authors":["Bang C. Huynh","Meilani Wibowo-Teale","Andrew M. Wibowo-Teale"],"abstract":"Symmetry provides a powerful machinery to classify, interpret, and understand quantum-mechanical theories and results. However, most contemporary quantum chemistry packages lack the ability to handle degeneracy and symmetry breaking effects, especially in non-Abelian groups, nor are they able to characterize symmetry in the presence of external magnetic or electric fields. In this article, a program written in Rust entitled QSym$^2$ that makes use of group and representation theories to provide symmetry analysis for a wide range of quantum-chemical calculations is introduced. With its ability to generate character tables symbolically on-the-fly, and by making use of a generic symmetry-orbit-based representation analysis method formulated in this work, QSym$^2$ is able to address all of these shortcomings. To illustrate these capabilities of QSym$^2$, four sets of case studies are examined in detail in this article: (i) high-symmetry $\\textrm{C}_{84}\\textrm{H}_{64}$, $\\textrm{C}_{60}$, and $\\textrm{B}_9^-$ to demonstrate the analysis of degenerate molecular orbitals (MOs); (ii) octahedral $\\textrm{Fe(CN)}_6^{3-}$ to demonstrate the analysis of symmetry-broken determinants and MOs; (iii) linear hydrogen fluoride in a magnetic field to demonstrate the analysis of magnetic symmetry; and (iv) equilateral $\\textrm{H}_3^+$ to demonstrate the analysis of density symmetries.","url_abs":"https://arxiv.org/abs/2310.06749v2","url_pdf":"https://arxiv.org/pdf/2310.06749v2.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":"qsym-2-a-quantum-symbolic-symmetry-analysis","repo_url":"https://gitlab.com/bangconghuynh/qsym2","is_official":1,"mentioned_in_paper":0,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}