Further details can be found in Supplementary Note 1. Total 22,709 bulk structures of binary alloys were generated, where 7,391 structures were fully relaxed to calculate formation energies and the remaining 15,318 were later used for screening. The calculated bulk structures consist of 297 elemental combinations (Figure ). In addition to 2e-ORR dataset which is biased toward binary materials, Wang-Botti-Marques (WBM) dataset was also used for validation to confirm a versatility of our model. The WBM dataset was generated by the elemental substitution of crystal structures in MP with chemically similar elements, containing sufficiently universal data (86 elements, 168,237 unique compositions and 257,486 structures). The amount of data in the WBM was further increased by an iterative scheme, where desirable candidates in each batch were used to generate additional candidates in the following batch. For testing Wren (Roost), the canonicalization was also applied to 2e-ORR and WBM dataset, reducing the number of data to 5,406 (2,325) and 224,498 (168,215), respectively.