How Accurately Can DFT Describe Non-valence Anions? - Archive ouverte HAL Access content directly
Journal Articles Journal of Chemical Theory and Computation Year : 2023

How Accurately Can DFT Describe Non-valence Anions?

Guillaume Thiam
Franck Rabilloud

Abstract

Weakly bound non-valence anions are molecular systems where the excess electron stabilizes in a very diffuse orbital whose size, shape, and binding energy (∼ 1 − 100 meV) are governed by the long-range electrostatic potential of the molecule. Its binding energy comes mainly from charge-dipole or charge-multipole interactions, or dispersion forces. While highly correlated methods, like coupled cluster methods, are considered to be the state of the art for describing anionic systems, especially when the electron lies in a very diffuse orbital, we consider here the possibility to use DFTbased calculations. In such molecular anions, the outer electron experiments long-range exchange and correlation interactions. We show that DFT can describe long-range bound states provided that a correct asymptotic exchange and correlation potential is used, namely, that from a range-separated hybrid functional. This opens an alternative to the computationally demanding highly correlated method calculations. It is also suggested that the study of weakly bound anions could help in the construction of new DFT potentials to study systems where non-local effects are significant.
Fichier principal
Vignette du fichier
Manuscrit_Nonvalence_anions_JCTC2023merged.pdf (3.1 Mo) Télécharger le fichier
Origin Files produced by the author(s)

Dates and versions

hal-04156373 , version 1 (08-07-2023)

Identifiers

Cite

Guillaume Thiam, Franck Rabilloud. How Accurately Can DFT Describe Non-valence Anions?. Journal of Chemical Theory and Computation, 2023, 19 (10), pp.2842-2849. ⟨10.1021/acs.jctc.3c00099⟩. ⟨hal-04156373⟩
10 View
58 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More