Viviane's Projects
Dynamics of x-ray excited states
The electronic and nuclear dynamics of excited states in x-ray region
have been studied by time dependent wave packet propagation technique.
Recently, I started the investigation of the dynamic of proton
transfer in the core ionized state of water dimer (Fig.1). The hydrogen bond
changes drastically when the core hole is created in donor oxygen.
Contrary to the ground state the global minimum is shifted to the proton
transfer region. We expected to observe this proton transfer state using
x-ray photoelectron spectroscopy. However, we recognized soon that the
corresponding change of the photoelectron spectrum is too small due to
rather short time of the
propagation of the wave packet in the proton transfer region comparing with
the lifetime of core-ionized state (Fig.2). Our current simulations show
that the infrared + x-ray pump-probe spectroscopy is a proper tool to
evidence the formation of the proton transfered state in the core ionized
state of water dimer (Fig.3).
Figure 1 - Geometrical structure of ground state of water dimer.
Figure 2 - Wave packet propagation in core ionized potential surface
of water dimer.
Figure 3 - Potential curves of the core ionized and ground
states of water dimer.
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