Strengths and limitations of the adiabatic exact-exchange kernel for total energy calculations - Tout INSP Accéder directement au contenu
Article Dans Une Revue Journal of Chemical Physics Année : 2023

Strengths and limitations of the adiabatic exact-exchange kernel for total energy calculations

Résumé

We investigate the adiabatic approximation to the exact-exchange kernel for calculating correlation energies within the adiabatic-connection fluctuation–dissipation framework of time-dependent density functional theory. A numerical study is performed on a set of systems having bonds of different character (H2 and N2 molecules, H-chain, H2-dimer, solid-Ar, and the H2O-dimer). We find that the adiabatic kernel can be sufficient in strongly bound covalent systems, yielding similar bond lengths and binding energies. However, for non-covalent systems, the adiabatic kernel introduces significant errors around equilibrium geometry, systematically overestimating the interaction energy. The origin of this behavior is investigated by studying a model dimer composed of one-dimensional, closed-shell atoms, interacting via soft-Coulomb potentials. The kernel is shown to exhibit a strong frequency dependence at small to intermediate atomic separation that affects both the low-energy spectrum and the exchange-correlation hole obtained from the corresponding diagonal of the two-particle density matrix.
Fichier principal
Vignette du fichier
JCP23-AR-00551.pdf (1.27 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-04095368 , version 1 (11-05-2023)

Identifiants

Citer

Maria Hellgren, Lucas Baguet. Strengths and limitations of the adiabatic exact-exchange kernel for total energy calculations. Journal of Chemical Physics, 2023, 158 (18), pp.187107. ⟨10.1063/5.0146423⟩. ⟨hal-04095368⟩
25 Consultations
23 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More