Breit interaction effects in relativistic theory of the nuclear spin-rotation tensor

AUCAR, IGNACIO AGUSTÍN; GOMEZ, SERGIO SANTIAGO; GIRIBET, CLAUDIA GLORIA; RUIZ DE AZÚA, MARTÍN CÉSAR

JOURNAL OF CHEMICAL PHYSICS

AMER INST PHYSICS

Lugar: New York; Año: 2013 vol. 139 p. 94112 - 94118

0021-9606

In this work, relativistic effects on the nuclear spin-rotation (SR) tensor originated in the electronnucleusand electron-electron Breit interactions are analysed. To this end, four-component numericalcalculations were carried out in model systems HX (X=H,F,Cl,Br,I). The electron-nucleus Breitinteraction couples the electrons and nuclei dynamics giving rise to a purely relativistic contributionto the SR tensor. Its leading order in 1/c is of the same value as that of relativistic correctionson the usual second order expression of the SR tensor considered in previous work [I. A. Aucar,S. S. Gómez, J. I. Melo, C. G. Giribet, and M. C. Ruiz de Azúa, J. Chem. Phys. 138, 134107(2013)], and therefore it is absolutely necessary to establish its relative importance. For the sakeof completeness, the corresponding effect originating in the electron-electron Breit interaction isalso considered. It is verified that in all cases these Breit interactions yield only very small correctionsto the SR tensors of both the X and H nuclei in the present series of compounds. Results of thepresent work strongly suggest that in order to achieve experimental accuracy in the theoretical studyof the SR tensor both electron-nucleus and electron-electron Breit effects can be safely neglected.