electronvolt

https://doi.org/10.1351/goldbook.E02014
Non-SI unit of energy, eV ≈ 1.602176487(40) x 10E-19 J.
Sources:
CODATA 2006 (https://doi.org/10.1103/RevModPhys.80.633)
Green Book, 2nd ed., p. 75 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)
PAC, 1996, 68, 957. 'Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)' on page 971 (https://doi.org/10.1351/pac199668040957)