https://doi.org/10.1140/epjd/e2005-00013-1
On the accuracy of valence–shell computations for heavy and super–heavy elements
Institut für Physik, Universität Kassel, 34132 Kassel, Germany
Corresponding author: a s.fritzsche@physik.uni-kassel.de
Received:
30
September
2004
Revised:
17
December
2004
Published online:
1
February
2005
Recent atomic computations on the (super–) heavy elements have raised
the expectation that their low–lying excitation and ionization energies
can be calculated with an accuracy of a few hundredth of an eV and, hence,
that such computations might help in the identification of new lines.
For most many–electron atoms, however, the higher–order relativistic and
quantum electrodynamical (QED) effects are included so far only in a rather
approximate form. Using different model computations for the neutral and weakly
ionized ytterbium (Z = 70) and nobelium atoms (Z = 102), it is
shown here that QED effects alone may lead to an uncertainty of 20–50 meV for
the excitation energies of all super–heavy elements, and that even for
highly–correlated wave functions the theoretical predictions are presently
not more accurate than about 0.1 eV. Moreover, in order to support forthcoming
spectroscopic measurements on the elements beyond Z = 100,
detailed computations have been carried out for
the two low–lying 
excitation energies of
nobelium by using systematically enlarged multiconfiguration Dirac–Fock
wave functions.
PACS: 31.25.-v – Electron correlation calculations for atoms and molecules / 32.70.Cs – Oscillator strengths, lifetimes, transition moments
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
