Bimetallic nanoparticles (NP), or nanoalloys, are widely studied due to their applications in optics, magnetism, catalysis, and other energy-related applications . The large number of possible metal combinations offers ample opportunities for adapting to very specific applications and property requirements. For example, the chemical (and resulting catalytic) properties of bimetallic materials can be tailored for activating different reactions by the choice of metals and their relative concentration . However, determining the structures formed when combining two metals is challenging, even for bulk mixtures crystallizing into fcc-like lattices . Surfaces and NPs involve even more complex spaces of nonequivalent chemical orderings , which is why most studies determining the stable structure of large bimetallic NPs have focused on identifying the most stable chemical orderings only for fixed particle shapes, i.e. the most stable homotop .