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Aufsatz
State-dependent volume isotope shifts of low-lying states of group-IIa and -IIb elements
(1985)
Results of relativistic multiconfiguration Dirac-Fock calculations with an extended nucleus are used to analyze the volume isotope shifts of the resonance transitions in the group-IIa and -IIb elements
as well as in Yb. This is done together with a review of the isotope shift theory, including a critical evaluation and comparison of the semiempirical calculation of volume isotope shifts commonly
used today. Electronic factors F_i, proportional to differences of electronic densities over the nuclear volume, are ...
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
Spin-polarized Hartree-Fock-Slater calculations in atoms and diatomic molecules with the finite element method
(1990)
We present spin-polarized Hartree-Fock-Slater calculations performed with the highly accurate numerical finite element method for the atoms N and 0 and the diatomic radical OH as examples.
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
Ions of the superheavy elements in vacuum and in solution
(1976)
The extension of the Periodic Table into the range of unknown atomic numbers of above
one hundred requires relativistic calculations. The results of the latter are used to indicate probable values for X-ray transition lines which will be useful for identification of the atomic species formed
during collision between accelerated ions and the target. If the half-lives of the isotopes are long, then the chemistry of these new species becomes an important question which is reviewed for E110, E 111
and E112.
The ...
Aufsatz
A clear atomic example for the surface sensitivity of penning ionization
(1990)
Using a crossed-beam apparatus with a double hemispherical electron spectrometer,
we have studied the spectrum of electrons released in thermal energy ionizing collisions of metastable
He^*(2^3S) atoms with ground state Yb(4f^14 6s^2 ^1S_0) atoms, thereby providing the first Penning electron spectrum of an atomic target with-4f-electrons. In contrast to the HeI (58.4nm) and NeI (73.6/74.4nm)
photoelectron spectra of Yb, which show mainly 4f- and 6s-electron emission in about a 5:1 ratio, the He^*(2^3S) Penning ...