Born Sept. 10th, 1933 in Vienna (Austria).
Student of chemistry at Bonn 1952-1954 and Freiburg in Breisgau 1954-1960.
Research interests: Electron correlation in atoms and molecules. Magnetic properties of molecules. Relativistic quantum chemistry. Theory of the chemical bond and of intermolecular forces. Author of the book Einführung in die Theoretische Chemie in 2 volumes.
Received the Carl-Duisberg memorial price of the German Chemical Society in 1971, the Liebig medal of the German Chemical Society in 1996, the Schrödinger medal 1995 of WATOC, the Dionyz Ilkovic medal of the Slovak Academy of Sciences in 1998, and the Erich-Hückel-Preis 2016 der Gesellschaft Deutscher Chemiker (GDCh). Member of the International Academy of Quantum Molecular Sciences.