Topics
Research topics in the theoretical chemistry group
Intermolecular force fields
Intermolecular potential surfaces or, as they are often called,
noncovalent force fields, determine many properties of matter. They
include both weak Van der Waals forces and hydrogen bonding, which lead
to the formation of supramolecular systems and play an important role in
most biological processes. A longstanding activity of the Theoretical
Chemistry group is the ab initio calculation of intermolecular
potentials by quantum mechanical methods for a series of well-chosen
model systems, also studied experimentally. The methods used are either
based on symmetry-adapted perturbation theory (SAPT, for closed-shell
systems) or on supermolecular coupled-cluster methods (for both open-
and closed-shell systems).
Dynamics of molecular clusters and collisional processes
The intra- and intermolecular energy transfer and relaxation processes
that occur in molecular aggregates when they are excited or when the
molecules collide are very interesting. State-to-state studies by
molecular beam techniques and laser spectroscopy provide detailed
information on these processes, but theory is needed to understand what
happens and to relate the observed properties to the underlying
intermolecular force fields. The Theoretical Chemistry group performs
quantum dynamics calculations for bound states and photodissociation of
Van der Waals and hydrogen bonded clusters, as well as for (in)elastic
molecular scattering. At the same time, since intermolecular forces
cannot be directly measured, it is very useful that the comparison of
the results of dynamics calculations with experimental data provides a
critical test of the intermolecular potentials. Also aggregates
containing (unstable) radicals or electronically excited species are
being investigated.
State-to-state chemical reactions; theoretical approach.
Experimentally, chemical reactions can be studied at the state-to-state
level in molecular beams. To guide and interpret such experiments
theoretical studies are indispensable. We have been working on the
development and application of time-independent and time-dependent
quantummechanical methods and also on semiclassical and quasiclassical
methods. Particularly the quantummechanical methods are very
compute-intensive, but also semiclassical calculations become more and
more demanding if the number of coordinates treated quantummechanically
increases. Standard program packages are not available and software
development is an important part of the work. Recently, our research has
focussed on (in)elastic and reactive collisions of ultracold molecules
and radicals, which can be extremely well controlled with the use of
electric and magnetic fields.
Recent publications
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Institute for Molecules and Materials |
Radboud University Nijmegen]
Last updated: January 16, 2007, by Gerrit C. Groenenboom,
e-mail: gerritg@theochem.ru.nl.