[1] He made contributions to nuclear spectroscopy, coincidence measurement techniques, radioactive tracers for biochemistry and medicine, and neutron optics.

Maier-Leibnitz was in the field of atomic physics, and he discovered metastable, negative helium ions, which later had applications in particle accelerators.

[Note: After World War II, the KWImF was renamed the Max-Planck Institut für medizinische Forschung.

Maier-Leibnitz worked on nuclear spectroscopy, electron-gamma-ray coincidence measurements, radioactive tracers, and energy conservation in Compton scattering.

In 1942, he returned to continue his work with Bothe, who, since 1939, had been a principal in the German nuclear energy project, also known as the Uranverein (Uranium Club).

Riehl was an authority on the purification of uranium, and he greatly contributed to bringing about the construction of a new research tool at the Technische Hochschule München.

This reactor, popularly called the Atomei (atomic egg), based on its characteristic shape, was built in 1956 and became operational in 1957.

Other members of the Nuclear Physics Working Group in both 1956 and 1957 were: Werner Heisenberg (chairman), Hans Kopfermann (vice-chairman), Fritz Bopp, Walther Bothe, Wolfgang Gentner, Otto Haxel, Willibald Jentschke, Josef Mattauch, Wolfgang Riezler [de], Wilhelm Walcher and Carl Friedrich von Weizsäcker.

For the first decade of nuclear energy development in the Federal Republic of Germany (FRG), it was the center of decision making, and it had representative membership from German industry.

Also in 1961, Rudolf L. Mößbauer, a former student of Maier-Leibnitz at Technische Hochschule München, received the Nobel Prize in Physics for his discovery of recoil-free emission and absorption of gamma radiation in solids known as the Mößbauer Effect, which led to numerous applications in solid state physics, chemistry, biophysics, medicine and archeology.

Maier-Leibnitz, along with his colleagues Wilhelm Brenig, Nikolaus Riehl and Wolfgang Wild, in a memorandum in 1962, proposed the establishment of a Physics Department at the Technische Hochschule München.

This was used as bargaining tool to bring Mößbauer from the California Institute of Technology in Pasadena back to the Technische Hochschule München in 1964.

Maier-Leibnitz was instrumental, along with Louis Néel, in bringing about the German-French project to construct a high-flux neutron source and founded the Institut Laue-Langevin in Grenoble in 1967, named in honor of the physicist Max von Laue and Paul Langevin.