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Dissertation
Relativistic LCAO with Minimax Principle and New Balanced Basis Sets
(2011-01-13)
Relativistic density functional theory is widely applied in molecular calculations with heavy atoms, where relativistic and correlation effects are on the same footing. Variational stability of the Dirac Hamiltonian is a very important field of research from the beginning of relativistic molecular calculations on, among efforts for accuracy, efficiency, and density functional formulation, etc. Approximations of one- or two-component methods and searching for suitable basis sets are two major means for good projection ...
Aufsatz
Relativistic effects in physics and chemistry of element 105. [Part] I.
(American Institute of Physics, 1992)
A detailed study of the electronic structure and bonding of the pentahalides of group 5 elements V, Nb, Ta, and element 105, hahnium (and Pa) has been carried out using relativistic molecular cluster Dirac-Slater discrete-variational method. A number of calculations have been performed for different geometries and molecular bond distances. The character of the bonding has been analyzed using the Mulliken population analysis of the molecular orbitals. It is shown that hahnium is a typical group 5 element. In a great ...
Aufsatz
Reduced L_1 level width and Coster-Kronig yields by relaxation and continuum interactions in atomic zinc
(1992)
Calculations of the level width \gamma( L_1) and the f_12 and f_13 Coster-Kronig yields for atomic zinc have been performed with Dirac-Fock wave functions. For \gamma(L_1), a large deviation between theory and evaluated data exists. We include the incomplete orthogonality of the electron orbitals as well as the interchannel interaction of the decaying states. Orbital relaxation reduces the total rates in all groups of the electron-emission spectrum by about 10-20 %. Different, however, is the effect of the continuum ...
Aufsatz
An attempt on the calculation of relativistic potential energy curves: noble gas difluorides
(1980)
Total energy SCF calculations were performed for noble gas difluorides in a relativistic
procedure and compared with analogous non-relativistic calculations. The discrete
variational method with numerical basis functions was used. Rather smooth potential
energy curves could be obtained. The theoretical Kr - F and Xe - F bond distances were calculated to be 3.5 a.u. and 3.6 a.u. which should be compared with the experimental values of 3.54 a.u. and 3.7 a.u. Although the dissociation energies are off by a factor of ...
Aufsatz
Inclusive probability calculations for the K-vacancy transfer in collisions of S{^15+} on Ar
(1992)
Using the single-particle amplitudes from a 20-level coupled-channel calculation with ab initio relativistic self consistent LCAO-MO Dirac-Fock-Slater energy eigenvalues and matrix elements we calculate within the frame of the inclusive probability formalism impact-parameter-dependent K-hole transfer probabilities. As an example we show results for the heavy asymmetric collision system S{^15+} on Ar for impact energies from 4.7 to 16 MeV. The inclusive probability formalism which reinstates the many-particle aspect ...
Aufsatz
Multiple vacancy inclusive probabilities for the scattering system 16 MeV S{^16+} on Ar
(1991)
To evaluate single and double K-shell inclusive charge transfer probabilities in ion-atom collisions we solve the time-dependent Dirac equation. By expanding the timedependent wavefunction in a set of molecular basis states the time-dependent equation reduces to a set of coupled-channel equations. The energy eigenvalues and matrix elements are taken from self-consistent relativistic molecular many-electron Dirac-Fock-Slater calculations. We present many-electron inclusive probabilities for different final configurations ...
Dissertation
A computer-algebraic approach to the study of the symmetry properties of molecules and clusters
(2006-06-19)
This thesis work is dedicated to use the computer-algebraic approach for dealing
with the group symmetries and studying the symmetry properties of molecules and clusters.
The Maple package Bethe, created to extract and manipulate the
group-theoretical data and to simplify some of the symmetry applications,
is introduced. First of all the advantages of using Bethe
to generate the group theoretical data are demonstrated. In the current version,
the data of 72 frequently applied point groups can be ...
Dissertation
Beschreibung von Oberflächenphänomenen durch relativistische Clusterrechnungen unter Verwendung eines Einbettungsverfahrens
(2005-02-02)
For the theoretical investigation of local phenomena (adsorption at surfaces, defects or impurities within a crystal, etc.) one can assume that the effects caused by the local disturbance are only limited to the neighbouring particles. With this model, that is well-known as cluster-approximation, an infinite system can be simulated by a much smaller segment of the surface (Cluster). The size of this segment varies strongly for different systems. Calculations to the convergence of bond distance and binding energy of ...
Dissertation
First-principles electronic theory of non-collinear magnetic order in transition-metal nanowires
(2015-05-27)
The structural, electronic and magnetic properties of one-dimensional 3d transition-metal (TM)
monoatomic chains having linear, zigzag and ladder geometries are investigated in the frame-work of
first-principles density-functional theory. The stability of long-range magnetic order along the
nanowires is determined by computing the corresponding frozen-magnon dispersion relations as a
function of the 'spin-wave' vector q.
First, we show that the ground-state magnetic orders of V, Mn and Fe linear chains at ...
Dissertation
Polarization and correlation phenomena in the radiative electron capture by bare highly-charged ions
(2003)
In dieser Arbeit wird die Wechselwirkung zwischen einem Photon und einem Elektron im starken
Coulombfeld eines Atomkerns am Beispiel des radiativen Elektroneneinfangs beim Stoß hochgeladener
Teilchen untersucht. In den letzten Jahren wurde dieser Ladungsaustauschprozess insbesondere
für relativistische Ion–Atom–Stöße sowohl experimentell als auch theoretisch ausführlich erforscht. In Zentrum standen dabei haupsächlich die totalen und differentiellen Wirkungsquerschnitte.
In neuerer Zeit werden vermehrt Spin– und ...