Data Review: Theory of aggregation of nitrogen in diamond

Modelling defects using atomistic and quantum–mechanical techniques provides us with a powerful method for identifying the microscopic structure of centres observed in experiment. Properties including the energies and lifetimes of optical transitions, local vibrational modes and vibrational resonances have proved particularly powerful for nitrogen in diamond. However, processes involving the motion of nitrogen through the lattice are still not fully understood, and the literature is noticeably sparse concerning the modelling of these problems. Several levels of theory can be applied to the simulation of defects in crystalline material, ranging from potentials gained from parameterisation using experimental observations, to so–called ab initio which use no experimental input, the details of which are in the literature...