Small nickel clusters: Two low-lying Ni3 states

Matrix isolation IR spectroscopy and quantum-chemical calculations were jointly used to identify the system of bands related to Ni 3 clusters. The positions of two low-lying electronic states were determined, and vibrational frequencies and geometry in the ground and excited states were estimated. In all the calculated states, Ni 3 had the structure of an isosceles triangle. In the X 3 B 2 ground and a 3 B 1 lower excited states, this was an acute-angled triangle. In the b 3 B 2 and c 3 B 1 excited states, the triangle was obtuse-angled.