electronic transition 

https://doi.org/10.1351/goldbook.08245
Transition in an atom, ion, or molecule from an electronic energy level E1 to another energy level E2.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 657 [Terms] [Paper]