To determine the effect of Spin Orbit Coupling (SOC) on predicting final energies, we performed PBE+SOC for 11 different heavy-metal elements selected based on ref . As we found the inclusion of SOC had little effect on the ranking of low-energy structures, to maintain the consistency of the QCD data we have not included SOC-predicted total energies and atomic structures in the QCD database. More discussion of the effects of SOC, including simple linear equations for estimating SOC-calculated energies from the energies reported in the QCD, can be found in section 5 and section 6 of the SI.