Ulrich Deiters was born in 1953. He studied chemistry at the Ruhr University of Bochum (Germany), where he, under the supervision of Gerhard M. Schneider, obtained his doctorate in physical chemistry in 1979. He then joined the groups of Keith E. Gubbins and William B. Streett at the Cornell University, Ithaca (USA). After his return to Bochum he founded his own research group. He served for many years as chairman of the IUPAC Subcomittee on Thermodynamic Data. In 1993 he became a professor of physical chemistry at the University of Cologne, from where he formally retired in 2018. His main research fields are the thermodynamics and statistical thermodynamics of fluid mixtures, Monte Carlo simulation, prediction of thermodynamic data ab initio from quantum mechanical calculations, and the development of mathematical methods for the prediction of phase diagrams. Thomas Kraska was born in 1964. He studied chemistry at the Ruhr University of Bochum (Germany), where he, under the supervision of Ulrich K. Deiters, obtained his doctorate in physical chemistry in 1992. He then joined the group of Keith E. Gubbins at Cornell University, Ithaca (USA) for two years, followed by a research stay for 6 months in the group of Kenneth S. Pitzer at UC Berkeley (USA). He returned to Cologne University in Germany and founded his own research group. In 1999 he obtained his habilitation and continued in Cologne with research on molecular thermodynamics, MD simulation, and the nucleation and growth of metallic and pharmaceutical nanoparticles. At present he is active in the field of chemical education, fostering physical chemistry, mathematization, and molecular simulation in secondary chemistry education.