A modified core-valence-Rydberg Becke's three-parameter exchange (B3) + Lee-Yang-Parr (LYP) correlation (CVR-B3LYP) functional is proposed in order to calculate core-excitation energies of third-row atoms with reasonable accuracy. The assessment of conventional exchange-correlation functionals shows that the appropriate portions of Hartree-Fock (HF) exchange for core-excited-state calculations depend on shells: 70% and 50% for K-shell and L-shell excitations, respectively. Therefore, the modified CVR-B3LYP functional is designed to use the appropriate portions of HF exchange, 70%, 50%, and 20%, for K-shell, L-shell, and valence regions separately. Time-dependent density functional theory calculations with the modified CVR-B3LYP functional yield both K-shell and L-shell excitation energies with reasonable accuracy. The modified CVR-B3LYP also provides valence-excitation energies and standard enthalpies of formation accurately. Thus, the modified CVR-B3LYP describes all of the K-shell, L-shell, and valence electrons appropriately.
ASJC Scopus subject areas
- Computer Science Applications
- Physical and Theoretical Chemistry