Description of plasmon-like band in silver clusters: The importance of the long-range Hartree-Fock exchange in time-dependent density-functional theory simulations

Franck Rabilloud (1)

1 ILM - Institut Lumière Matière [Villeurbanne]

Absorption spectra of Ag₂₀ and Ag^q₅₅ (q = +1, −3) nanoclusters are investigated in the framework of the time-dependent density functional theory in order to analyse the role of the d electrons in plasmon-like band of silver clusters. The description of the plasmon-like band from calculations using density functionals containing an amount of Hartree-Fock exchange at long range, namely, hybrid and range-separated hybrid (RSH) density functionals, is in good agreement with the classical interpretation of the plasmon-like structure as a collective excitation of valence s-electrons. In contrast, using local or semi-local exchange functionals (generalized gradient approximations (GGAs) or meta-GGAs) leads to a strong overestimation of the role of d electrons in the plasmon-like band. The semi-local asymptotically corrected model potentials also describe the plasmon as mainly associated to d electrons, though calculated spectra are in fairly good agreement with those calculated using the RSH scheme. Our analysis shows that a portion of non-local exchange modifies the description of the plasmon-like band.

Mots clés: Absorption spectroscopy; Hybrid density functional calculations; Nanoclusters; Generalized gradient approximations; Self consistent field methods; Plasmons; Leptons; Becke; three-parameter; Lee-Yang-Parr; Transition metals; Time dependent density functional theory

Domaines: Chimie; Physique [physics]; Sciences de l'ingénieur [physics]

Franck Rabilloud. Description of plasmon-like band in silver clusters: The importance of the long-range Hartree-Fock exchange in time-dependent density-functional theory simulations. Journal of Chemical Physics, 2014, 141 (14), pp.144302. ⟨10.1063/1.4897260⟩. ⟨hal-02309832⟩