Directors and research fellows from 1954 until 1958

Alfred Klemm (1913-2013) started as employee in 1939 at the Kaiser Wilhelm Institute (KWI) for Chemistry. In 1944 Alfred Klemm discovered an isotope separation of silver that transferred into solid silver iodide by using a mass spectrograph. Three years later Klemm and his staff discovered that the effect can also be observed in molten salts. In 1954, Alfred Klemm habilitated at the University of Mainz about the "thermodynamics of transport processes in ion mixtures and its application to isotope-containing salts and metals." Before being appointed as Research Fellow at the MPIC in 1958, he worked as a guest scientist at Chalmers University of Technology in Gothenburg.

In collaboration with the theoretical physicist Ludwig Waldmann (also a research Fellow at the MPIC) Klemm also carried out gas-kinetic experiments. He was able to show that not only isotopes can be separated by using thermal diffusion, but also molecules that differ in their moment of inertia only. In 1981, Klemm ended his active time at the MPIC.

Klemm was also active as publisher. Together with Hans Friedrich-Freksa he founded the journal of natural science (Zeitschrift für Naturforschung) in 1946. In 1982 he reactivated the Dieterich'sche publishing house (Dieterich’sche Verlagsbuchhandlung) in Mainz.

Ludwig Waldmann (1913-1980). In 1943 he became a member of the Kaiser Wihelm Institute for Chemistry in Berlin. When the Institute moved, he moved with it; first to Tailfingen and then to Mainz. Waldmann received an appointment as a Scientific Fellow at the Max Planck Institute for Chemistry in 1954. In 1963 he accepted a position as professor at the University of Erlangen-Nürnberg and left Mainz, but he remained an External Scientific Member of the MPIC.

Waldmann’s research focused on questions about theoretical physics and he made a number of theoretical and experimental contributions to gas kinetics. He investigated the thermal diffusion effect and the concomitant pressure and temperature dependence as well as the relationships of Onsager symmetry. In 1957 he extended the so-called Boltzmann equation to apply it to gases with rotating molecules (Waldmann-Snider equation) and developed a theory of diffusion. In addition, he explored the physical properties of a Lorentz's rigid electron.

In 1961 it was his idea that instigated the investigation of various gas-kinetic behaviors of hydrogen molecules of the same mass, such as D₂. In collaboration with Josef Mattauch and his research group, Waldmann developed a new method of mass spectral dispersion determination which made possible a very exact evaluation of mass spectra.

Hermann Kümmel (1922-2012) had been a Scientific Member of the Max Planck Institute for Chemistry from 1964 to 1969. In 1969 he accepted a position as professor for theoretical physics at the University of Bochum, but remained an External Scientific Member of MPIC.

The Berlin-born physicist did his PhD in 1952 at the Free University of (West) Berlin on quantum electrodynamics. Three years later he published his habilitation treatise on the quantum mechanical reasoning of thermodynamics. After spending time at the Iowa State University (USA) and at the University of Tübingen, Hermann Kümmel joint the Max Planck Institute for Chemistry in August 1959. He started as theoretical assistant and dealt with many-body systems (e.g. atomic nuclei).

In cooperation with Fritz Coester Kümmel succeeded in 1958 in developing the “coupled cluster” method to calculate the properties of many-body systems. It soon became the standard method in quantum chemistry for calculating properties of atoms and molecules. After being appointed as Scientific Member at MPIC in 1964 Hermann Kümmel also became leader of the theoretical group in the division of Nuclear Physics.