Geometry optimizations were carried out in Cartesian coordinates using L-BFGS algorithm, as implemented in DL-FIND 135 . The default thresholds of 1x10 -6 hartree for self-consistent field (SCF) convergence and 4.5x10 -4 hartree/bohr for the maximum gradient were used. Level shifting 136 of 0.25 Ha on all virtual orbitals was employed to aid with SCF convergence. All singlet states were calculated with a restricted formalism while the non-singlet states were calculated with an unrestricted formalism. For 95 out of 96 SCO complexes, calculations were performed in the singlet, triplet, and quintet spin states using low-T crystal structures in all cases. Despite the fact that we do not use the high-T crystal structure as a starting point for geometry optimizations, we make comparison of the final optimized structure bond lengths to the respective low-T and high-T bond lengths, making the curation of both low-T and high-T structures necessary. For one SCO complex (refcode: IXAQEF) with a radical ligand, calculations were performed in the doublet, quartet, and sextet spin states. However, we discard this SCO complex from analysis because the spin did not localize to the radical ligand equivalently in all spin states and refer to the final set of 95 SCO complexes as SCO-95.