Angles Dihedrals In all PSO algorithms, the procedure terminates after a pre-defined number of steps or when improvements over the objective function become minimal. To allow a parameters-free usage of Swarm-CG, simple heuristics enable automatic selection of a relevant swarm size and number of swarm iterations to perform in each cycle of optimization. Swarm size (𝑆 𝑠𝑖𝑧𝑒 ) is defined according to the dimension (𝐷) of the search space as 𝑆 𝑠𝑖𝑧𝑒 = 2 + √𝐷 and number of swarm iterations (𝑆 𝑖𝑡𝑒𝑟 ) as 𝑆 𝑖𝑡𝑒𝑟 = 8 + √𝐷 2