2025/09/16 by Ibrahim E. Awad, Awad, Ibrahim E., Abd Al‐Aziz A. Abu‐Saleh +7
Chemical Engineering · Chemistry · Materials Science · #Catalysis and Oxidation Reactions #Catalytic Processes in Materials Science #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Radioactive element chemistry and processing
paper · pdf · doi:10.48550/arxiv.2509.12580
openalex publication_date 2025/09/16 · openalex created_date 2025/10/18 · openalex updated_date 2026/07/28
The components of the radial correlation energy density are calculated and analyzed for the atoms from He to Ar. The components include the nucleus-electron potential correlation energy density, the kinetic correlation energy density and the electron-electron potential correlation energy density. The necessary correlated one and two-electron density matrices are obtained from the Extrapolated-Full-Configuration-Interaction (exFCI) wave function where the reference wave function is restricted Hartree-Fock (RHF) or restricted open-shell Hartree-Fock (ROHF) depending on whether the atom is closed or open-shell. The accuracy associated with integrating the HF and exFCI energy density components, and the correlation energy density components, is evaluated on the SG-1 and SG-2 atomic grids. The SG-1 grid provides atomic energies that are accurate to about 1 kJ mol-1, with the exception of the kinetic energy. The SG-2 grid is required for the analysis of atomic kinetic energies and more subtle energetic effects. There is also a significant amount of integration error cancellation in the correlation energy densities. The radial correlation energy densities display notable shell structure, and there is a substantial difference between the α and β-electron correlation energy densities for the open-shell atoms.