Influence of spin-orbit coupling on electronic structures of TM@Au12 (TM=3d, 4d, and 5d atoms)

► The SOC can generally disperse much the frontier orbitals of the clusters. ► The HOMO-LUMO gaps and spin moments in Au clusters are decreased much by the SOC. ► Only the SOC systems with closed-shells or 'closed-orbitals' obey the Ih2 group. ► The spin and orbital moments are both quenched for the systems obeying Ih2 group.