vacuum level at infinity

symbol: $E_{\rm{VAC}}(\infty)$
https://doi.org/10.1351/goldbook.09301
Electric potential of the vacuum at a point in space.
Notes:
  1. In electron spectroscopy, the point in space is taken at a sufficiently large distance outside the sample, such that electric fields caused by different work functions of different parts of the surface are zero or extremely small.
  2. This level is not experimentally accessible.
See also: vacuum level
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1818 (https://doi.org/10.1515/pac-2019-0404)