About the project
The aim of this research is to develop and demonstrate capabilities to explore hydrogen diffusion mechanisms and paths in actinide materials. As a further target, investigation of surface adsorption of hydrogen will be carried out to understand how hydrogen enters the bulk to diffuse and how this process is affected by surface termination and conditions such as pressure and temperature, or even presence of solvents.
The computational simulation of chemical reactions in materials requires an accurate, explicit description of their electrons. This can be achieved by quantum mechanical calculations from first principles, in particular with Density Functional Theory (DFT) which achieves a good balance between accuracy and computational efficiency.
DFT calculations are typically limited to tens of atoms due to the steep increase of the computational effort with the number of atoms. Recent developments have led to “linear-scaling” reformulations of DFT which allow calculations with thousands of atoms which can be ideal in cases of complex systems requiring more realistic models. Amongst these, the ONETEP program is a leading linear-scaling DFT approach because it retains the full accuracy of conventional cubic-scaling DFT calculations.
The accurate computation of diffusion at the DFT level will provide major new insights into the processes that happen during operation and storage. This will involve also collaboration with our industrial partner AWE, subject to contract agreement, who will provide guidance on the most relevant materials.
An important technical advantage that ONETEP will provide here is that we will be able to simulate models with several thousand atoms achieving structures and concentrations of defects that are closer to reality than with smaller models with conventional DFT. Extensive access to supercomputing resources will be provided for these simulations via local and national facilities.
