ERC Advanced Grant for research into pollution, molecular collisions

Researchers Bas van de Meerakker and Jan Hendriks have both been awarded an Advanced Grant from the European Research Council (ERC) to extend their research.

ERC Advanced Grants are awarded annually to exceptional, innovative and ground-breaking research. The recipients can use this grant to continue their research for the next five years. A total of 1829 European projects will receive an allocation this round, including two from Radboud University.


Led by Jan Hendriks, professor of Environmental Science at the Radboud Institute for Biological and Environmental Sciences, the PowerOfSize project will receive 2.5 million euros. This project looks at chemical pollution, one of the fastest growing environmental problems in the world. Various tools are available to determine the risks of thousands of substances to thousands of plant and animal species, including humans. Unfortunately, due to financial and ethical constraints, the data needed to calibrate these models is often lacking.

Previous research has shown that the values of parameters in those models can depend on the size of molecules, regions and organisms. However, that relationship is often not directly proportional: if a city, lake or animal is twice as big, twice as much energy, water or material does not necessarily flow in or out.

This project therefore derives relationships for parameters that determine the dispersion, accumulation and effects of substances. General principles can then be developed that are valid in different fields, for example for emission and excretion of substances by engines and animals, flow rates in rivers and in blood vessels, and concentrations of natural and synthetic particles. By nature, the research is thus both fundamental and applied: the "Power of Size" contributes to a better understanding of the role played by size in the functioning of systems as well as to a better assessment of risks of substances.


Bas van de Meraakker, professor of Spectroscopy of Cold Molecules at Radboud University’s Institute for Molecules and Materials, will a 3.3 million euro ERC Advanced Grant for the QUCUMBER project. Meerakker’s research involves the study of molecular collisions at the lowest possible energy. At low energies the wave-character of matter leads to exotic scattering phenomena that reveal the fundamental mechanisms of molecular collisions. Crossed beam methods are ideal to probe collisions with the highest detail, but the lowest energy currently achievable is not sufficient to fully harvest these possibilities.

Building upon Meerakker’s recent breakthrough in state-to-state merged beam scattering at record-low energies, the aim of this project is to reduce the currently attainable collision energy by another two to three orders of magnitude by combining Stark deceleration, merged beams, laser cooling and velocity map imaging. Using two distinct systems that are characteristic for a large class of molecular interactions, the QUCUMBER project will measure hitherto unexplored quantum features in the state-to-state integral and differential cross sections.

For atom-molecule systems, the researchers will measure scattering resonances and image how the resonance region dominated by a few partial waves evolves into the pure quantum regime where only a single partial wave remains. For collisions between dipolar molecules, they will experimentally study a peculiar self-polarizing effect, probing fundamental features of the long-range dipole-dipole interaction that can be steered from attractive to repulsive. For both systems, they will manipulate the cross sections using external electric fields, and study how the partial waves transform during the collision.

The proposed research program will directly visualize how molecular collisions transform from "hot" into "ultracold" at the full quantum mechanical level, providing excellent tests for quantum theories of molecular interactions. It will bridge the gap between the ultracold quantum physics and physical chemistry communities, and will lay the foundations for a new era in the rich history of elucidating molecular reaction dynamics using crossed molecular beams.