Apart from playing a pacesetting role in transforming classical physical chemistry, preoccupied with electro- and thermochemistry, into chemical physics, focused on structure and later on dynamics, Haber's Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry made key contributions to early quantum physics, in particular to confirming Bohr’s atomic theory. With the founding in 1919 of the department of physics and the appointment of James Franck as its head, the institute became a testbed for experimental quantum physics research. Among the topics tackled at the institute by Franck and his coworkers were electron scattering by gases as well as accurate spectroscopic measurements, which corroborated with precision the existence of the quantized energy levels foretold by Bohr’s atomic theory. After Franck left for Göttingen in 1921, Haber's institute continued making key contributions to quantum physics through the pioneering work of H. Kallmann (confirmation of the Compton effect; development of the molecular beam method), K.F. Bonhoeffer and P. Harteck (separation of para-hydrogen), R. Ladenburg (lightscattering and dispersion), H. Kopfermann (nuclear multipole moments) and, last but not least, E. Wigner (the role of symmetry in quantum physics).

This presentation is based on work co-authored by Bretislav Friedrich.