Structure and properties of Ni7 cluster isomers

First principles calculations based on molecular orbital theory as well as molecular dynamics simulation using a many body interatomic potential reveal the existence of two nearly degenerate isomeric forms of Ni7-a capped octahedron and a pentagonal bipyramid. Contrary to expectations, the magnetic moments of the two isomers are the same. Although the reactivity of the isomers with N2 is different, it is argued that the current experimental studies of N2 saturation coverage cannot confirm the coexistence of the two isomers. Further experiments are necessary to achieve this goal.