Title : Tracking the degradation of organic compounds from reactive molecular dynamics simulations

Germain Salvato Vallverdu : [email protected]

Scientific Context
Contamination of surface and groundwater with organic compounds (pharmaceutics compounds, pesticides …) is a major concern due to the hazards these chemicals pose to the environment and humans. Depending on their aqueous solubility, the chemicals either remain in the soil or enter surface waters and groundwaters. The products that result from their degradation can remain in animals, vegetables and water sources, and are gradually enriched through the food chain. Because of the toxicity of certain compounds, even at trace levels, there is increasing interest in the development of systems to monitor, break down, and/or remove them.

Objectives
The current project concerns the investigation of the chemical reactivity using molecular dynamics simulations and focuses on the degradation processes of pollutants. In this scope, the main objective of this PhD project is to enforce reactive molecular simulations applied to the degradation processes of organic compounds by considering both the thermodynamic and kinetic aspects of the reactivity. To that ends, the candidate will develop new methods in order to obtain reliable reactive FF for the considered compounds and improve the ReaxFF model itself.

Work plan
First of all, in order to investigate the degradation mechanisms of pesticides and chemicals, the ReaxFF parameters set has to be extended. To that ends, a training set containing conformers and reactive paths of the relevant compounds and their degradation products has to be built and target properties will be computed using quantum mechanical techniques. This quite difficult task will be tackled down by combining global optimizers that had been adapted to ReaxFF parameterization and homemade codes for the production and extraction of data from quantum chemistry calculations.
This will be achieved by the validation of the FF against experimental results. In particular, the coupling between molecular simulations and analytical chemistry experiments conducted using the high level instrumental facilities available in the IPREM institute will be implemented. At then end, you will consider the development of a robust and general procedure for the parameterization of ReaxFF.

Contact and Application

The candidates must have knowledge in

• Physical chemistry and numerical simulation. Experience in molecular dynamics will be appreciated.
• Be proficient in numerical tools: Linux/Unix console, HPC server. Programming skills will be appreciated.

The candidates must demonstrate

• a good organization
• ability to present results issued from its research
• ability to work in a multidisciplinary team and to be capable of caring himself

Contact:

Germain Salvato Vallverdu : [email protected]