{"paper":{"title":"Hund and anti-Hund rules in circular molecules","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.chem-ph"],"primary_cat":"cond-mat.mes-hall","authors_text":"A. Manolescu, D. C. Marinescu, M. Nita, M. Tolea","submitted_at":"2017-11-16T09:34:42Z","abstract_excerpt":"We study the validity of Hund's first rule for the spin multiplicity in circular molecules - made of real or artificial atoms such as quantum dots - by considering a perturbative approach in the Coulomb interaction in the extended Hubbard model with both on-site and long-range interactions. In this approximation, we show that an anti-Hund rule {\\it always} defines the ground state in a molecule with $4N$ atoms at half-filling. In all other cases (i.e. number of atoms {\\it not} multiple of four, or a $4N$ molecule away from half-filling) both the singlet and the triplet outcomes are possible, a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1711.06001","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}