The xTB methods, GFN1-xTB and GFN2-xTB, enable efficient screening of the potential energy surface (PES), facilitating the analysis of crystal polymorphs, adsorption behaviors, and solid-solid transition states. Molecular dynamics simulations are an invaluable tool for elucidating crystal structures. In particular, GFN2-xTB was used to investigate ligand interactions in MOFs, adsorption behavior, and transitioning between polymorphs. Though GFN has positioned itself as an efficient and robust TB parametrization for materials research, it has its limitations. The direct application of the xTB methods could be chal-lenging for certain types of solids, such as metals, 180 radicals or charged molecules with double or triple bonds. Additionally, a benchmark study on crystalline organic semiconductors has highlighted difficulties in applying GFN2-xTB for periodic systems due to unphysical geometries. 183 However, the same study also demonstrates reasonable performance of GFN1-xTB on similar systems.