3.1 influence of level of theory on quality of parameters. We first assessed the impact of different functionals (D3BJ-PBE0 and ωB97X-D3) and basis sets (def2-SVP and def2-TZVP) on the quality of the parameters obtained from the Seminario method (Figure ). The results obtained for the different benchmarks were similar regardless of the functional and basis set used. Surprisingly, despite the reference values being derived from calculations at the ωB97X-D3/def2-TZVP level of theory, parameters obtained at this level of theory were not better than those obtained at the D3BJ-PBE0/def2-SVP level of theory. This observation suggests that the loss of accuracy during parametrization originates from the inadequate depiction of interactions by conventional force fields. Since D3BJ-PBE0/def2-SVP is computationally efficient, it is used as a default methodology to parametrize templates in metallicious.