International Workshop on Atomic Interactions in Laser Fields
- Abstracts
An ab initio study of the modifications of
atomic and molecular Rydberg states in the condensed phase
Ch. Kolczewski and V. Staemmler
Lehrstuhl für Theoretische Chemie,
Ruhr-Universität Bochum, D-44780 Bochum, Germany
The question of how atomic and molecular Rydberg spectra are
modified if the atom or molecule is placed into a condensed phase
is addressed for two systems.
- Li atoms in He cages of different size and
composition. While the 2s ground state of the Ci atom is always
destabilized by neighboring He atoms, the higher Rydberg levels
exhibit a variety of modifications, with barriers on several
potential curves, spd mixing, strong changes of oscillator
strengths and so forth. The origin of these modifications are
explained in a series of model calculations, the changes in the
Rydberg spectra are simulated and the question whether the
effects are additive is addressed.
- N(1s) NEXAFS spectra of isolated N2,
of single N2 molecules adsorbed on an oxide surface
and of N2 in the condensed phase. For the
interpretation of NEXAFS spectra of adsorbed molecules it is of
crucial importance how the low-lying (bound) resonances and the
Rydberg states are modified by the interaction with the surface
and possible electronic surface states and whether large shifts
between gas phase and the condensed are to be expected. This
question is investigated by calculating π*
resonances and Rydberg states for core (i.e. 1s) excited levels
of N2, N2/TiO2(110) and bulk N2.
For both systems, quantum chemical ab initio calculations are
performed at the SCF, frozen-core SCF, CASSCF and CI levels.