Lifetimes of negative-ion states near metal surfaces

Energy shifts and broadening of negative-ion states near metal surfaces are calculated using the complex-scaling technique. The affinity levels of the atoms are described using a nonlocal pseudopotential derived with use of the separable-potential method. The affinity levels shift downward with decreasing atom-surface separation. The widths of the affinity levels are found to be narrow compared to the width of typical excited states.