Surface core-level shift
= Surface core-level shift
{title2=$\Delta E_B=E_B^{\rm surface}-E_B^{\rm bulk}$}
A difference in the binding energy of the same core level for surface and bulk atoms of one material. Reduced coordination changes bonding and local potential; the relaxation that screens the photoemission core hole also changes. A measured shift combines these initial- and final-state effects and cannot by itself be converted into a unique local charge.