Communication: Can excitation energies be obtained from orbital energies in a correlated orbital theory?

Linearity condition for orbital energies in density functional theory (III): Benchmark of total energies

This study presents a numerical assessment of total energy related physical quantities estimated using the orbital-specific (OS) global and range-separated hybrid functionals, designed to satisfy the linearity condition for orbital energies (LCOE). The numerical assessment demonstrates that accurate evaluation of the reaction energies, reaction barrier, and dissociation curve can be achieved vi...

Excitation energies from density functional perturbation theory

We consider two perturbative schemes to calculate excitation energies, each employing the Kohn– Sham Hamiltonian as the unperturbed system. Using accurate exchange-correlation potentials generated from essentially exact densities and their exchange components determined by a recently proposed method, we evaluate energy differences between the ground state and excited states in first-order pertu...

2A04 Reactivity index based on orbital energies

Ionization Potential, Electron Affinity, Electronegativity, Hardness, and Electron Excitation Energy: Molecular Properties from Density Functional Theory Orbital Energies

Representative atomic and molecular systems, including various inorganic and organic molecules with covalent and ionic bonds, have been studied by using density functional theory. The calculations were done with the commonly used exchange-correlation functional B3LYP followed by a comprehensive analysis of the calculated highest-occupied and lowest-unoccupied Kohn-Sham orbital (HOMO and LUMO) e...

Orbital energies and negative electron affinities from density functional theory: Insight from the integer discontinuity.

Orbital energies in Kohn-Sham density functional theory (DFT) are investigated, paying attention to the role of the integer discontinuity in the exact exchange-correlation potential. A series of closed-shell molecules are considered, comprising some that vertically bind an excess electron and others that do not. High-level ab initio electron densities are used to calculate accurate orbital ener...