A new parameterization for copper at the INDO/CI level is presented. Results for excitation energies, ionization potentials, and electron detachment energies are presented for selected copper clusters with up to ten atoms. The parameterization gives improved results for calculations of spectroscopic properties for systems with significant copper-copper interactions, such as clusters and model surfaces. Results for the Ols shakeup of CO attached to Cu(100) model surfaces for the new parameters are compared with experiments and with results obtained using the standard parameters.

INDO/CI calculations were used to analyze the C1s and O1s shake-up spectra of nickel tetracarbonyl, Ni(CO)₄. The satellite structure in both cases is dominated by excitations from metal–ligand bonding (2Π_b) to metal–ligand antibonding (2Π_a) orbitals and by excitations within the core-ionized CO molecule, Π_CO—Π*_CO.

In the chemisorption system CO/Ni(100), a comparison between available high resolution core level photoelectron spectra and spectra calculated by the INDO/CI method done for different nickel cluster sizes. A reassignment of some of the satellites is made. It is found that the asymmetry and the broadening of the main line mainly depends on substrate-substrate excitations, predominantly from the d-band to the s-band within the nickelsubstrate.