A new family of star-like icosahedral structures for small cobalt clusters

► First principles calculation of cobalt clusters structures under different approaches. ► Unexpected icosahedral growth pattern of cobalt clusters with 20-25 atoms. ► Effects of magnetism in the stabilization of cobalt clusters with 13-26 atoms. ► Comparison of Ionization potential and electron affinity with experiments supports the new cluster structures. ► Non-crystalline structure of cobalt clusters isomers are compared to crystalline one.