interface to DFTB+ in library mode to perform Ehrenfest and RP-Ehrenfest

[reinimaurer1]

Just an idea: DFTB+ can be compiled in library mode and one can interact with DFTB+ which exposes many important variables. This is currently being explored in the context of QM/QM embedding with FHI-aims/ChemShell.

It might be interesting to look into an interface with libdftb (direct FORTRAN calls from JL) to perform Ehrenfest dynamics. DFTB+ could perform the electronic propagation and would deliver the forces to be used in MD or RPMD mode.