On nd bonding in the transition metal trimers: Comparison of Sc3 and Y3

Abstract

CASSCF/CCI calculations are presented for the low-lying states of Y3. Comparison of the wave functions for Y3 and Sc3 indicates substantial 4d-5p hybridization in Y3, but little 3d-4p hybridization in Sc3. The increased 4d-5p hybridization leads to stabilization of 4dpi bonding with respect to 4dsigma bonding for equilateral triangle Y3, and also leads to 4d-5p bonding for linear geometries. These effects lead to a different ordering of states for equilateral triangle geometries and a smaller excitation energy to the linear configuration for Y3 as compared to Sc3