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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.
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Comparison between experiment and theory in heavy electronic systems
(Gräff, G. (Hrsg.), 1981)
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Relativistic many-electron SCF correlation diagram for Pb-Pb
(Fabian, Derek J. (Hrsg.), 1981)
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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.
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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.
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Estimation of the ground state correlation energy for isoelectronic series of 2 to 20 electrons
(1987)
Correlation energies for all isoelectronic sequences of 2 to 20 electrons and Z = 2 to 25 are obtained by taking differences between theoretical total energies of Dirac-Fock calculations and experimental total energies. These are pure relativistic correlation energies because relativistic and QED effects are already taken care of. The theoretical as well as the experimental values are analysed critically in order to get values as accurate as possible. The correlation energies obtained show an essentially consistent ...
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Relativistic atomic level calculations with nuclei carrying additional fractional charges
(1983)
One-electron energy levels and wavelengths have been calculated for Na-like ions whose nuclei carry quarks with additional charges ±e/3, ±2e/3. The calculations are based on relativistic self-consistent field procedures. The deviations from experimental values exhibit regularities which allow an extrapolation for the wavelengths of 3s - 3p, 3s - 4p, 3p - 3d, and 3p - 4s transitions for the nuclear charge Z = 11± 1/3, ±2/3. A number of transitions are found in the region of visible light which could be used in an ...
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Contribution of the exact Breit operator plus the electron state-dependent screening to the multiplet and fine structure of muon-electron atoms
(1980)
We investigate for very general cases the multiplet and fine structure splitting of muonelectron atoms arising from the coupling of the electron and muon angular momenta,including the effect of the Breit operator plus the electron state-dependent screening. Although many conditions have to be fulfilled simultaneously to observe these effeets, it should be possible to measure them in the 6h- 5g muonic transition in the Sn region.
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Volume isotope shifts in low lying transitions of Au I
(1984)
Electronic factors in the volume isotope shift have been calculated in an ab initio way with the relativistic Dirac-Fock method for a number of different optical single/and two-photon transitions in Au I. The agreement with a semi-empirical method is within 10% for the resonance transition. For this one and a few other transitions the effect of core excitation has been analyzed with the Multi-configuration Dirac-Fock method as well, and it was found to reduce the electronic factor in the order of 5 %.