Richard Stephen Berry (April 9, 1931[1] – July 26, 2020) was an American professor of physical chemistry.
At the University of Chicago, he has been a member of the department of chemistry, the James Franck Institute, the College, and, for many years, the Committee and then the School of Public Policy Studies.
Rice and John Ross, another with Linda Gaines and Thomas V. Long, another with Vladimir Kazakov, Stanislaw Sieniutycz, Zbigniew Szwast, and Anatoly Tsirlin, and one with Boris Smirnov.
He then went on to study alkali halides in the gas phase, first at the University of Michigan and then at Yale, using shock waves to produce sufficient dissociation of the molecules to ions to make it feasible to observe the photodetachment spectra of the halide ions, thus determining the electron affinities of the halogen atoms to four or five significant figures.
This work, in turn, stimulated what has become known as "finite-time thermodynamics," the study of the optimal performance of processes constrained to operate in finite time or at nonzero rates.