Our method works for defects with the same symmetry in ground and excited state, which could not necessarily be treated by existing methods.
This is accomplished by using a cluster calculation with TD-DFT and applying a low frequency cutoff to recreate the solid-state.
The low frequency cutoff is shown to eliminate vibrational modes unique to the surface of the cluster, and demonstrates a connection between cluster and solid-state.
Furthermore, our cluster calculation demonstrates the first vibrationally resolved ab-initio photoluminescence spectrum of NV- centres in nanodiamonds.
Our method has been recently published in Journal of Applied Physics.