Radical systems can usually only be described by QC methods (not force fields, FF). The potential energy surface can still be explored using FF to obtain a broad set of initial structures, but FF parameters should be carefully checked to prevent e.g., radical centers being treated as ions. Nevertheless, exploration at e.g., XTB level of theory is more suitable. Further, high-level QC methods should be used to describe these open-shell systems (freezing problematic parts might be helpful, especially during initial optimizations). The QC results should also be checked for spin contamination, where relevant.