Atomic ionization: sd energy imbalance and Perdew-Zunger self-interaction correction energy penalty in 3d atoms

• 成果类型: Article
• 署名作者: Maniar, Rohan; Shukla, Priyanka B.; Johnson, J. Karl; Jackson, Koblar A.; Perdew, John P.
• 署名单位: Tulane University; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; Central Michigan University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11990
• DOI: 10.1073/pnas.2418305122
• 发表日期: 2025-03-11
• 关键词: generalized gradient approximation; densities; exchange

摘要

To accurately describe the energetics of transition metal systems, density functional approximations (DFAs) must provide a balanced description of s-and d-electrons. One measure of this is the sd transfer error, which has previously been defined as E(3dn-14s1) - E(3dn-24s2). Theoretical concerns have been raised about this definition due to its evaluation of excited-state energies using ground-state DFAs. A more serious concern appears to be strong correlation in the 4s2 configuration. Here, we define a ground-state measure of the sd energy imbalance, based on the errors of s-and d-electron second ionization energies of the 3d atoms, that effectively circumvents the aforementioned problems. We find an improved performance as we move from the local spin density approximation (LSDA) to the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) to the regularized and restored Strongly Constrained and Appropriately Normed (r2SCAN) meta-GGA for first-row transition metal atoms. However, we find large (similar to 2 eV) ground-state sd energy imbalances when applying a Perdew-Zunger 1981 self-interaction correction. This is attributed to an energy penalty associated with the noded 3d orbitals. A local scaling of the self-interaction correction to LSDA results in a balance of s-and d-errors.