for the dihedral angles χ 1 and χ 2 , as shown in Figure , utilizing both target and reference potential, as well as 1-D torsion scans for selected combinations of χ 1 and χ 2 shown in Figure . The torsion profile generated with ANI-2x and the one reported in for the semiempirical SCC-DFTB potential 56 are qualitatively similar. Note that different definitions for χ 1 were used, hence, the χ 1 axis of the 2-D scans is shifted by 180 • . While for SCC-DFTB the two minima at (χ