Negative Electron Affinities and Derivative Discontinuity Contribution from a Generalized Gradient Approximation Exchange Functional

Abstract

Two methods to calculate negative electron affinities systematically from ground-state density functional methods are presented. One makes use of the lowest unoccupied molecular orbital energy shift provided by approximate inclusion of derivative discontinuity in the nearly correct asymptotic potential (NCAP) nonempirical, constraint-based generalized gradient approximation exchange functional. The other uses a second-order perturbation calculation of the derivative discontinuity based on the NCAP exchange-correlation potential. On a set of thirty-eight molecules, NCAP leads to a rather accurate description that is improved further through the perturbation correction. The results presented show the importance of the asymptotic behavior of the exchange-correlation potential in the calculation of negative electron affinities as well as demonstrating the versatility of the NCAP functional.

Enhancing Conductivity of Silver Nanowire Networks through Surface Engineering Using Bidentate Rigid Ligands

“…We performed geometry relaxations to determine the equilibrium structure of the adsorbed ligands and thus obtain w b . We then extracted the energies of the ligand molecular orbitals with respect to the Ag Fermi energy and applied many-body and image charge corrections to the semilocal DFT values to obtain E b . − Further details are provided in the Methods section, and the details related to the calculated E b values are given in Table S2.…”

“…Specifically, we obtained the correction to the HOMO as the difference between the Delta self-consistent field (ΔSCF) ionization potential and the position of the PBE HOMO energy with respect to the vacuum. We then followed the procedure proposed in ref and took the LUMO correction to be equal and opposite to the HOMO correction, a method which has been found to be reasonably accurate and avoids the difficulties associated with computing electron affinities with ΔSCF. Then, we used a classical image-charge expression to account for the screening response of the Ag to the excited electron, placing the image plane 1 Å above the Ag surface.…”

Solvent‐free oxidation of straight‐chain aliphatic primary alcohols by polymer‐grafted vanadium complexes

“…Hence, IP and EA were calculated by using the following equations, respectively. [ 40 ] …”

Density Functional Prediction of Quasiparticle, Excitation, and Resonance Energies of Molecules With a Global Scaling Correction Approach

“…For a set of 38 molecules proposed in Tozer and De Proft (2005), the resulting MAE is as small as 0.18 eV with the aug-cc-pVTZ basis set. Recently, a similar accuracy has been reached by the explicit inclusion of derivative discontinuity in the GGA exchange potential (Carmona-Espíndola et al, 2020). In this section, we extend our calculation to 26 new molecules that are beyond the above mentioned works, and hence expand the test set to a total of 64 molecules.…”

“…The good accuracy was made possible because of the use of the global scaling correction (GSC) (Zheng et al, 2011), which will be introduced later. At the same time, another method has been developed to evaluate the negative EA from the GKS eigenvalue of the neutral ground states (Carmona-Espíndola et al, 2020). Different from GSC, this method is designed to impose the derivative discontinuity of the exact XC potential.…”