Abstract
This work presents quantumchemical und quantumdynamical simulations on the
state specific vibrational excitation and photodissociation of HNO3.
The first part deals with the calculation of ab initio
potential energy surfaces for a twodimensional model
which treats the OH- and the NO-single- bonds explicitly.
Both the MP2 and CASSCF methodes are applied to
determine the ground and the lowest three excited electronic
states, respectively. The calculations yield good agreement with
experimental data.
Based on the ab initio potential of the
electronic ground state,
the vibrational eigenfunctions are calculated.
These eigenfunctions are investigated by means of
zero-order states to examine the coupling between
the two degrees of freedom.
In the second part, the laser-driven molecular dynamics
is simulated using quantum dynamical techniques.
Starting from the lowest vibrational eigenfunction of the ground
electronic state, highly excited vibrational
bound states as well as states lying in
the continuum are prepared selectively using
using ultrashort IR laser pulses.
In addition, the
length of NO bound can be controlled
at any time by adjusting the
phaserelation within the two selective IR laser pulses.
The continuum states prepared by a sequence of two
ultrashort pulses show a quasi-coherent vibration
in the dissociative continuum of the ground electronic
state.
Monitoring these vibrations by femtosecond IR+UV
pump-probe spectroscopy is simulated using molecular
wavepacket propagation.
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