Effect of on-site Coulomb interactions on the electronic structure and magnetic property of Gd2 cluster

To understand the intriguing magnetic property of the Gd2 cluster, we performed first-principles electronic structure calculations. A reduced coordination drives the cluster to have different electronic and magnetic properties from its bulk counterpart. The on-site Coulomb interaction, U, is found to be important for the moment enhancement, whereas its magnetic ground state does not change as a function of U. The orbital-decomposed magnetic moments show that 6s and 5d electron contributions become significant. From fully relativistic calculations we found that the effect of spin–orbit coupling on the magnetic moment is not significant and the orbital moment remains small.