CNDO model and interpretation of the photoelectron spectrum of CO chemisorbed on Ni

CNDO calculations for CO chemisorbed on a cluster of 10 Ni atoms produce a pattern of valence orbital energy levels that agrees well with the experimental photoelectron spectrum of CO adsorbed on Ni; thus allowing the experimental energies to be assigned to specific orbitals. The bonding of the carbon atom to the Ni atom largely involves nickel s and p orbitals, with little contribution from the d orbitals.