STRUCTURE AND PROPERTIES OF NI-7 CLUSTER ISOMERS

First principles calculations based on molecular orbital theory as wel l as molecular dynamics simulation using a many body interatomic poten tial reveal the existence of two nearly degenerate isomeric forms of N i-7 - a capped octahedron and a pentagonal bipyramid. Contrary to expe ctations, the magnetic moments of the two isomers are the same. Althou gh the reactivity of the isomers with N-2 is different, it is argued t hat the current experimental studies of N-2 saturation coverage cannot confirm the coexistence of the two isomers. Further experiments are n ecessary to achieve this goal.