Dataset underlying a study on the streaming potential of an aqueous liquid jet, quantified by theoretical calculations and experimental data using photoelectron spectroscopy. Here we give the numerical procedure that was used to calculate the theoretical figures, and the underlying experimental data. All files are described in detail in the file _README.md . Curator of this data set: Uwe Hergenhahn (Orcid ID: 0000-0003-3396-4511, E-Mail: uhe@fhi-berlin.mpg.de). If you use any of these data for your scientific work, you are kindly asked to provide UH with some information about the form that this use had, and a citation if available.