First principles calculations on Ni impurities in Cu clusters

Structural and magnetic properties of small NiCuN-1 clusters are determined in the framework of Kohn-Sham density-functional theory (DFT). Besides some changes in bond length, the calculated structures for N⩽5 atoms are similar to those of pure CuN. For the optimal NiCuN-1 geometry the Ni ion occupies the most-coordinated atomic position and the ground-state corresponds to a minimum-spin configuration (Sz=0 or 12). Interesting correlations between cluster structure and magnetism are revealed by varying the total spin. The possible consequences of electron correlations and finite-temperature effects are briefly discussed.