I wonder if anyone here knows about additional atomic parameters and interactions sets for atoms not currently present in the DFTB parameter sets. The parameter sets are located at DFTB parameters. For example, I am interested in simulating systems that contain tetrafluoroborate anion, FB-(F)F. However, I have not across B-F interaction sets. Is anybody aware of a parametrization procedure to add new atomic interaction pairs to DFTB, or if any proprietary software already includes parameters beyond those provided at the link.
Thank you,