Structural dynamics

The time scale for electronic motion is that of attoseconds and for nuclear motion it ranges from femtoseconds for elementary processes, in particular photochemical processes that involve excited electronic states, to seconds or even longer for many biological processes. One wouldn’t necessarily characterize the timescales of biologically relevant processes in proteins as ultrafast, but no clear separations of timescales in their dynamics exist, so even the fastest processes need to be understood in order to predict the slower ones. Visualization of structural dynamics relies on probing techniques that are even faster than the events themselves and capturing dynamic processes in ‘real-time’ became possible with the advent of pico-, femto-, and attosecond sources delivering ultrashort pulses from the X-ray to the THz part of the spectrum. Specifically, with attosecond sources we can now observe the rearrangement or relaxation of the electronic excitations.

Within MUST, we have a unique combination of expertise in ultrafast MultiD spectroscopy, in ultrafast X-ray and electron diffraction, in X-ray absorption spectroscopy, in THz spectroscopy as well as in time-resolved photo electron spectroscopy. Additionally, MUST has a high concentration of competence in simulating the motion of electrons and nuclei in molecular compounds on various levels of theory, ranging from classical molecular dynamics simulations, over ab-initio based molecular dynamics on electronic ground and excited surfaces, up to a sophisticated quantum-dynamical treatment. To make efficient use of these simulation tools, also in view of the many collaborations between theoretical and experimental groups, MUST decided to purchase a large cluster computer. That is to say, the NCCR combines the required theoretical and experimental tools to address scientific problems within the grand challenges formulated above.

Research efforts within MUST not only aim at visualizing structural dynamics but also at controlling it through different means, such as catalysis on surfaces or optical pulse shaping techniques. Control is also an integral part of many experimental investigations, as it helps to disentangle difficult to interpret measurements.




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