In addition to SAAs, we have also considered dual-atom loys (DAAs) in our screening. DAAs are composed of a host and two different chemical elements A and B in close proximity, denoted (A, B)@host. DAAs have recently received attention since the synergy between the two atoms in these systems can be exploited to efficiently activate molecules, such as ethanol, and CO 2 . The design of DAAs is more challenging compared to the design of SAAs, as the number of possible combinations of elements and surface sites increases substantially. Hence, the SG rules could accelerate the discovery of DAA capable of activating CO 2 . For the DAA screening, we considered bridge sites of the following hosts and surface terminations Cu(100), Pd(111), and Pd(100). The 33 SA chemical elements highlighted in green and yellow in Figure were included in this screening. The number of DA bridge sites that can be constructed based on these SA and host surfaces is 1,488. The parameter r d-SA in Expression 5 is defined based on one SA element. Thus, to apply the constraint on r d-SA to the screening of surface sites in DAAs, we extended the definition of r d-SA by considering the average of the d-orbital radii of the two elements A and B in the DAA systems. The remaining parameters in 5 can be evaluated for DAAs using the definitions discussed previously.