State of an atom arising from its chemical interaction with neighbouring atoms in a molecule, compound, solid, liquid, or gas that leads to a characteristic energy or feature observable in electron spectroscopy.
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1822 (https://doi.org/10.1515/pac-2019-0404)