Predicting lanthanide cluster properties: A comparison with the observed optical spectra of Ho2

Abstract Ab initio pseudopotential calculations for Ho and Ho 2 have been carried out in order to support an assignment of the bands observed in UV-visible spectra of matrix isolated holmium species. SCF, MCSCF and configuration interaction (CI) procedures have been used with quasirelativistic pseudopotentials to compute the ground and excited state energies of Ho and Ho 2 , together with the dipole transition moments. For Ho 2 , using a Q = 11 pseudopotential (describing the holmium atom in the 4f 10 6s 2 5d 1 electronic state), two transitions from the ground state σ g 2 σ u 2 π u 2 to the states with principal excitations σ u → π g and π u → σ g ∗ are predicted at 499 and 524 nm. These two lines, with predicted close intensities, correlate nicely with the observed features at 498 504 and 558 563 nm in the spectrum of matrix-isolated Ho 2 .