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Aufsatz
Analysis of the electronic structure, hyperfine structure, and volume isotope shifts in the low lying states of BA I and BA II
(1988)
Relativistic multi-configuration Dirac Fock (MCDF) wavefunctions coupled to good angular momentum J have been calculated for low lying
states of Ba I and Ba II. These wavefunctions are compared with semiempirical
ones derived from experimental atomic energy levels. It is found that significantly better agreement is obtained when close configurations are included in the MCDF wavefunctions. Calculations of the electronic part of the field isotope shift lead to very good agreement with electronic factors
derived from ...
Aufsatz
Test for basis-set errors in relativistic Dirac-Fock-Slater calculations with a numerical AO-DFS-basis
(1987)
A fully relativistic four-component Dirac-Fock-Slater program for diatomics,
with numerically given AO's as basis functions is presented. We discuss the problem of the errors due to the finite basis-set, and due to the influence of the negative energy solutions of the Dirac Hamiltonian. The negative continuum contributions are found to be very small.
Aufsatz
Collision systems
(1984)
Various approximations which are possible for the theoretical description of colliding ion-atom systems are reviewed. With the emphasis on relativistic influences, a few comparisons of experimental results with relativistic calculations are made.
Aufsatz
Kr - Kr correlation diagram and its use in heavy-ion collisions
(1981)
A realistic self-consistent charge correlation diagram calculation of the Kr{^2+} - Kr{^2+} system has been performed. We get excellent agreement for the 4(3/2)_u level with an experimentally observed MO level at large distances. Possible reasons for discrepancies
between experiment and theory at small distances are discussed.
Aufsatz
Relativistic many-electron SCF correlation diagram for Pb-Pb
(Fabian, Derek J. (Hrsg.), 1981)
Aufsatz
Accurate Hartree-Fock-Slater calculations on small diatomic molecules with the finite-element method
(1988)
We report on the self-consistent field solution of the Hartree-Fock-Slater equations using the finite-element method for the three small diatomic molecules N_2, BH and CO as examples. The quality of the results is not only better by two orders of magnitude than the fully numerical finite difference method of Laaksonen et al. but the method also requires a smaller number of grid points.
Aufsatz
Ground state correlation energy of the Be-sequence for Z = 4-20 in MCDF approximation
(1989)
The ground state (J = 0) electronic correlation energy of the 4-electron Be-sequence is calculated in the Multi-Configuration Dirac-Fock approximation for Z = 4-20. The 4 electrons were distributed over the configurations arising from the 1s, 2s, 2p, 3s, 3p and 3d orbitals. Theoretical values obtained here are in good agreement with experimental correlation energies.
Aufsatz
Hyperfine structure and isotopic shift of the n^2 P_J levels (n = 7-10) of ^203,205 TI measured by Doppler-free two-photon spectroscopy
(1988)
Using Doppler-free two-photon absorption spectroscopy, we have measured hyperfine splitting constants as well as isotopic level shifts of the 6s^2 np ^2 P_l/2,3/2 states in (n=7-10) in ^203 TI and ^205 TI.
Calculations for hyperfine constants and electron density at the nucleus have been performed by the Dirac-Fock method. The experimental results are compared with these calculations as well as with
the predictions of the semiempirical theory.
Aufsatz
On the correlation between electric polarizabilities and the ionization potential of atoms
(1985)
It is found that the electric dipole polarizabilities of neutral atoms correlate very strongly with their first ionization potential within the groups of elements with the same angular momenta of the outermost electrons. As the latter values are known very accurately, this allows a very good
(<30%) prediction of various atomic polarizabilities.