with circles and squares, respectively. Representative structures corresponding to SCO complexes (refcodes: DUBFOY, 133 NERDIA, 134 and IZADUK 31 ) are shown as insets, and their data points are highlighted with orange circle, green circle, and red square, respectively. Hydrogen, boron, carbon, nitrogen, oxygen, and iron are shown in white, pink, gray, blue, red, and brown, respectively. The parity line is shown in solid gray in the plots.