This paper appears to calculate the Schrödinger equation solution for the hydrogen atom.
TODO is this the original paper on the Schrödinger equation?
Published on Annalen der Physik in 1926.
Open access in German at: onlinelibrary.wiley.com/doi/10.1002/andp.19263840404 which gives volume 384, Issue 4, Pages 361-376. Kudos to Wiley for that. E.g. Nature did not have similar policies as of 2023.
This paper may have fallen into the public domain in the US in 2022! On the Internet Archive we can see scans of the journal that contains it at: ia903403.us.archive.org/29/items/sim_annalen-der-physik_1926_79_contents/sim_annalen-der-physik_1926_79_contents.pdf. Ciro Santilli extracted just the paper to: commons.wikimedia.org/w/index.php?title=File%3AQuantisierung_als_Eigenwertproblem.pdf. It is not as well processed as the Wiley one, but it is of 100% guaranteed clean public domain provenance! TODO: hmmm, it may be public domain in the USA but not Germany, where 70 years after author deaths rules, and Schrodinger died in 1961, so it may be up to 2031 in that country... messy stuff. There's also the question of wether copyright is was tranferred to AdP at publication or not.
Contains formulas such as the Schrödinger equation solution for the hydrogen atom (1''):
where:
  • In order for there to be numerical agreement, must have the value
  • , are the charge and mass of the electron
English translation of papers that include the original Quantization as an Eigenvalue Problem by Schrödinger (1926).
Published on Nature at www.nature.com/articles/122990a0 and therefore still paywalled there as of 2023, it's ridiculous.
In 2024 it will fall into the public domain in the US.