samuel <dot> frost <at> warwick <dot> ac <dot> uk
PDF of the poster is available here!
The typical structure of an N2VH defect, the hydrogen is rapdily quantum tunnelling between equivalent carbons, giving it an averaged C3v symmetry in EPR!
The minimum energy path of a vacancy switching places with a carbon atom, calculated through DFT. The path is clearly crooked despite being in a periodic bulk cell.
The molecular dynamics simulation shows a vacancy moving from the bulk to the surface along the minimum energy path.
Since you cannot physically track a vacancy, as it does not exist, instead it's easiest to track atoms with fewer than 4 bonds.
The graph tracks the vacancy and shows its energy along the path to the surface.
There is a clear lowering of energy as the vacancy gets closer to the surface, implying there should be some form of diffusion gradient which could cause the destruction of the vacancy.