RESEARCH INTERESTS
Our research deals with theoretical and computational
aspects of molecular and materials sciences, with emphasis on the unified
treatment of physical and chemical kinetics using quantum molecular
dynamics. It includes collision-induced and photoinduced
phenomena in the gas phase, clusters, and at solid surfaces. Our aim is to
provide a fundamental approach to molecular dynamics, where electronic and
nuclear motions are consistently coupled to account for quantal
effects. We use quantum and statistical mechanics, mathematical, and
computational methods, to describe time-dependent phenomena (such as femtosecond dynamics and spectra) in both
simple and complex molecular systems.
In particular:
Quantum molecular dynamics.
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Spectra and dynamics of adsorbates on nanostructured
surfaces.
·
Energy transfer, electron
transfer and reactions in molecular collisions and at solid surfaces.
·
Intermolecular forces in ground and excited
electronic states.
·
Spectra and dynamics in atomic
clusters.
·
Photodissociation of polyatomic molecules.
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Photodesorption of molecules from solid surfaces.
·
Light emission in collisions of ions with atoms
and solid surfaces.
Theoretical methods.
·
Time-dependent many-electron
theory; time-dependent molecular orbital and time-dependent Hartree-Fock
approaches to molecular phenomena.
·
Density matrix theory of relaxation, dissipation
and fluctuations in extended molecular systems.
·
Statistical mechanics of response and rate processes.
·
Few-body and many-body theory
of molecular collisions; collisional time-correlation
approach to many-atom collisions.
Computational methods.
·
Numerical methods for the
solution of the Liouville-von Neumann differential
equation for the density operator.
·
Integration of stochastic differential equations
for coupled quantal and classical degrees of freedom,
and of the generalized Langevin equations.
·
Integration of differential equations for
coupled electronic and nuclear degrees of freedom. The
"relax-and-drive" method.
·
Calculation of molecular one- and two-electron
integrals for travelling atomic basis functions.
·
Numerical methods for the
solution of differential and integral equations of scattering.
·
Variational methods for scattering and time-dependent states.
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Path integral and wavepacket propagation in quantum dynamics.
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Constrained simulated annealing and constrained
molecular dynamics.
·
Operator algebra methods for
solving operator differential equations.
Computer visualization and animation of molecular
interactions.
·
Animation of the temporal
evolution of both nuclear motions and electronic densities using nuclear
trajectories and isocontours of electronic densities.
·
Animation of electronic transitions and electron
transfer obtained from time-dependent molecular orbitals.
·
Animation of light emission in
collisions of ions involving electronic rearrangement and the related transient
dipoles.