Chemical State Identification – BE Lookup Table – Ag to Zr

donated by B. Vincent Crist

All copyrights retained by B. Vincent Crist, senior editor of The XPS Library


Chemical State Identification Table – used in SDP v7.0 Software

(click on image or title – to OPEN full table)

” N*3 “   means that we used 3 BEs from NIST Database to produce an Average BE for that non-conductive (insulator) chemical compound.

  • In this table, the C (1s) BE used to Charge Reference (charge correct) all nonconductive materials (insulators) is 285.0 eV.   NIST database and makers use 284.8 eV.
  • The use of 285.0 eV for the hydrocarbon moiety (component) is based on extensive research on the C (1s) BE found on >50 native metal oxides, and >60 ion etched elements that collected UHV gases overnight.
  • More than 60 pure elements were scraped to remove oxides and other contamination in laboratory air, then  loaded into the main analysis chamber, and then strongly Argon ion etched clean (3-4 kV, 1- 10 minutes) in the main chamber.  Each ion etched clean pure element was then left inside the cryo-pumped chamber for 12-15 hours (overnight) to collect or to react with any of the UHV gases (CO, H2, CH4, CO2, O2, H2O, low molecular weight organics) that reside in the cryo-pumped analysis chamber, or the hydrocarbons that reside on the sample stage that was freshly loaded into the main chamber.


  • Conductive metals and conductive chemical compounds that exist in the NIST database are NOT included in this table due to the large number of uncertainties in the BE Calibrations and BE Scale that were used by those thousands of different contributors.
  • The largest uncertainty (not error) in the NIST collection of BEs occurs above 600 eV due to the differences in the Cu 2p3 calibration BE used by the different instrument manufacturers and the scientist who published.
  • The range of uncertainty can be as large as 0.6 eV because some instruments were calibrated to give a Cu (2p3/2) BE at 932.8 eV while others were calibrated to give a Cu (2p3/2) at 932.2 eV.  This range in the Cu (2p3/2) BE causes the BE scale to expand in a linear fashion with the high BE end suffering the larger uncertainty.