arXiv:2509.05509v1 Announce Type: new
Abstract: We report a highly accurate textit{ab initio} study of the ionization potential (IP) and electron affinity (EA) of element 119. Electronic correlation are treated within the relativistic coupled cluster theory including excitations up to quadruples. The Gaunt electron–electron interaction and quantum electrodynamic (QED) corrections are taken into account. The role of high-order correlation effects is analyzed in detail. Our recommended values for the IP and EA are 4.7839(56) eV and 0.6750(71) eV, respectively. These results tighten previous estimates and provide a reference point for future experiments probing periodic-law trends beyond oganesson.