Studying the Breit effects in actinides.

1) Petrov A.N., Mosyagin N.S., Titov A.V. 2) Tupitsyn I.I.
 1) Petersburg Nuclear Physics Institute 2) St.-Petersburg State University

In the present work we report the investigation of the low frequency Breit effects for actinides. For this purpose, the finite-difference (numerical) codes developed earlier for the Dirac-Hartree-Fock calculations with the
Breit interaction (DHFB) taken into account are applied. The contributions of both instantaneous magnetic (Gaunt) and retardation of the Coulomb interaction between electrons as well as contributions from/between
different shells are studied. The calculation of the Breit corrections to the valence and core properties for the uranium, plutonium and other atoms is performed. The quality of different relativistic effective core potentials
(RECPs) is studied with respect to the DHFB calculations.
The work of A.P., N.M. and A.T. was supported by RFBR (grant N 03-03-32335).
A.P. is grateful to the Ministry of Education of the Russian Federation ant
to St.-Petersburg Committee on Science and Higher Education for the
Grant N PD02-1.3-236. A.T. and N.M. were supported in part by
Scientific Program of St.Petersburg Scientific Center of RAS.