What was the title of Niels Bohr's 1913 paper on atomic structure?

Niels Bohr’s 1913 paper on atomic structure was titled “On the Constitution of Atoms and Molecules.”

Published in Philosophical Magazine, the paper appeared as a three-part series during 1913. It introduced Bohr’s revolutionary model of the atom, combining Ernest Rutherford’s nuclear atom with Max Planck’s quantum ideas. Bohr proposed that electrons could occupy only certain stable energy states rather than radiating energy continuously as classical physics predicted.

The first part dealt with electrons bound to positive nuclei; the second focused on systems containing a single nucleus; and the third examined systems with several nuclei. The model’s most famous success was its explanation of hydrogen’s spectral lines, including the previously known Balmer formula.

A common mix-up is confusing this title with “The Theory of Spectra and Atomic Constitution,” Bohr’s later 1922 book. “On the Constitution of Atoms and Molecules” is the 1913 paper series that established the Bohr model and helped launch modern quantum theory.