{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Paul Nee Matveeva R"],"funding":["Norges Forskningsr?d"],"pagination":["1533-1542"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC10910564"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["128(8)"],"pubmed_abstract":["We recently introduced the particle-breaking restricted Hartree-Fock (PBRHF) model, a mean-field approach to address the fractional charging of molecules when they interact with an electronic environment. In this paper, we present an extension of the model referred to as particle-breaking unrestricted Hartree-Fock (PBUHF). The unrestricted formulation contains odd-electron states necessary for a realistic description of fractional charging. Within the PBUHF parametrization, we use two-body operators as they yield convenient operator transformations. However, two-body operators can change only the particle number by two. Therefore, we include noninteracting zero-energy bath orbitals to generate a linear combination of even and odd electron states. Depending on whether the occupied or virtual orbitals of a molecule interact with the environment, the average number of electrons is either decreased or increased. Without interaction, PBUHF reduces to the unrestricted Hartree-Fock wave function."],"journal":["The journal of physical chemistry. A"],"pubmed_title":["Particle-Breaking Unrestricted Hartree-Fock Theory for Open Molecular Systems."],"pmcid":["PMC10910564"],"funding_grant_id":["275506","325574"],"pubmed_authors":["Paul Nee Matveeva R","Hoyvik IM","Folkestad SD","Sannes BS"],"additional_accession":[]},"is_claimable":false,"name":"Particle-Breaking Unrestricted Hartree-Fock Theory for Open Molecular Systems.","description":"We recently introduced the particle-breaking restricted Hartree-Fock (PBRHF) model, a mean-field approach to address the fractional charging of molecules when they interact with an electronic environment. In this paper, we present an extension of the model referred to as particle-breaking unrestricted Hartree-Fock (PBUHF). The unrestricted formulation contains odd-electron states necessary for a realistic description of fractional charging. Within the PBUHF parametrization, we use two-body operators as they yield convenient operator transformations. However, two-body operators can change only the particle number by two. Therefore, we include noninteracting zero-energy bath orbitals to generate a linear combination of even and odd electron states. Depending on whether the occupied or virtual orbitals of a molecule interact with the environment, the average number of electrons is either decreased or increased. Without interaction, PBUHF reduces to the unrestricted Hartree-Fock wave function.","dates":{"release":"2024-01-01T00:00:00Z","publication":"2024 Feb","modification":"2026-06-16T04:52:56.177Z","creation":"2025-04-05T11:38:14.844Z"},"accession":"S-EPMC10910564","cross_references":{"pubmed":["38351699"],"doi":["10.1021/acs.jpca.3c07231"]}}