Nuclear size effects in vibrational spectra - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Chemistry Chemical Physics Année : 2016

Nuclear size effects in vibrational spectra

Avijit Shee
Trond Saue

Résumé

We present a theoretical study of nuclear volume in the rovibrational spectra of diatomic molecules which is an extension of a previous study restricted to rotational spectra [Chem. Phys. 401 (2012) 103]. We provide a new derivation for the electron-nucleus electrostatic interaction energy which is basically independent of the choice of model for the nuclear charge distribution. Starting from this expression we derive expressions for the electronic, rotational and vibrational field shift parameters in terms of the effective electron density and its first-and second derivatives with respect to internuclear distance. The effective density is often approximated by the contact density, but we demonstrate that this leads to errors on the order of 10% and is furthermore not necessary since the contact and effective densities can be obtained at the same computational cost. We calculate the field shift parameters at the 4-component relativistic coupled-cluster singles-and-doubles level and find that our results confirm the experimental findings of Tiemann and co-workers [Chem. Phys, 68 (1982) 21, 1982, Ber. Bunsenges. Phys. Chem., 86 (1982) 821], whereas we find no theoretical justification for a scaling factor introduced in later work [Chem. Phys. 93 (1985) 349]. For lead sulfide we study the effective density as a function of internuclear distance and find a minimum some 0.2 Å inside the equilibrium bond distance. We also discuss Bigeleisen-Goeppert-Mayer theory of isotope fractionation in light of our results.
Fichier principal
Vignette du fichier
article_pccp (1).pdf (2.11 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01331176 , version 1 (29-01-2020)

Identifiants

Citer

Adel Almoukhalalati, Avijit Shee, Trond Saue. Nuclear size effects in vibrational spectra. Physical Chemistry Chemical Physics, 2016, 18, pp.15406-15417. ⟨10.1039/C6CP01913G⟩. ⟨hal-01331176⟩
59 Consultations
127 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More