1S core-level shifts of Al and Ar atoms in aluminum clusters

Theoretical 1s core-electron binding energies are presented for Al and Ar atoms in free space and in AlAl₁₂, AlAl₁₂Al₆, and ArAl₁₂ clusters. The binding energies have been calculated by the self-consistent field Xα scattered-wave (SCF Xα SW ) method using various exchange parameters and different atomic-sphere overlaps. The atom/cluster binding-energy shifts have been obtained both from the Slater's transition-state energies and from the total-energy differences; these values are in better agreement with each other if calculated with proper overlapping than if with nonoverlapping spheres. A comparison with available experimental and theoretical data is given as well.