Density functional calculations for copper clusters Cu and their monocarbonyls CunCO (n less than or equal to 13) have been performed using the relativistic ECP plus DZ basis set augmented by an f polarization function for copper atom. Equilibrium geometries, harmonic frequencies, and static mean polarizabilities of Cu-n and CunCO are determined. The feature of CO adsorption on the copper cluster and the effect of CO adsorption on stability and polarizability of the cluster are investigated.

Density functional theory with the B3LYP functional is used to calculate the equilibrium geometries and harmonic vibrational frequencies of nitryl halogenides XNO2 and XONO (X = F, Cl, Br, I). Stabilities and isomerizations of these isomers are investigated. Dissociation energies of the X-N bond in XNO2 are predicted at the B3LYP/6-311G* and QCISD(T)/ce-pvTZ levels. The electronic transition energies of the most stable XNO2 species have been estimated by time-dependent B3LYP calculations.