First-principles study of the stability and Jahn-Teller distortion of nickel clusters

The density functional method for molecules has been employed to study the structural and magnetic properties of Ni-N (N = 2-13) clusters. The calculated results show that the Jahn-Teller effect plays an important role in determining the ground state of certain geometric structures. Ground states have been assigned for these clusters. For Ni-5 and Ni-7, new ground states have been found. The second derivative of the binding energy with cluster size shows that besides N = 13, N = 10 is also a magic number. Most importantly, it is found that from N = 6 to 13, the spin moment is 8 mu(B) in all cases, which verifies the quantum confinement of 4s electrons in small nickel clusters. (c) 2005 Elsevier B.V. All rights reserved.