For example, the majority of complexes in the CSD are 3d TMCs of {Fe, Co, Ni, Cu} with coordinating atoms of {C, N, O}. This full set includes 10 coordination geometries based on the coordination number from 4 to 7, along with some nonstandard sandwich complexes. Since octahedral geometries are most common in this reported set, the distribution of the symmetry classes for all octahedral complexes were analyzed and more than 20 types of symmetry classes exist in this subset where the most common type is the geometry with two identical equatorial bidentate ligands and two identical axial monodentate ligands. Because this full data set was curated without any constraint, some erroneous complexes with missing hydrogens or disorder are present in this set, thus data preprocessing, such as re-examination and filtration is recommended to ensure a set of high-quality complexes for downstream tasks.