by: Department Head Gregory S. Girolami

I am sad to report that our colleague Don Secrest died suddenly on Saturday, May 10, 2014, at the age of 82. Born in Akron, OH, on January 3, 1932, he attended the University of Akron where he obtained his BS degree in 1955. He spent a year on a Fulbright Fellowship studying at the University of Erlangen in Germany, and then obtained his doctorate at the University of Wisconsin under Professor Joseph Hirschfelder in 1961, where he held a Monsanto Chemical Fellowship. Immediately after graduating, he joined our faculty as an Instructor in charge of the Departmental Computer Center. He was appointed Assistant Professor in 1963, Associate Professor in 1967, and Professor in 1981, retiring in 2000 after 39 years of active service. In 1971 he was a visiting professor at the University of Tokyo, and in 1972 and again in 1976 he was a visiting professor at the Max Planck Institute for Fluidic Research in Göttingen, and returned there in 1985 and 1986 as a Humboldt Professor. In 1978 he was a visiting professor at the National University in Mexico City. He was elected a Fellow of the American Physical Society, and served as Associate Editor of the Journal of Chemical Physics for four years; he was also a member of the editorial board of Chemical Physics. He was a member of the Phi Sigma Alpha and Sigma Xi fraternities (serving as the local chapter president of the latter).

Don carried out theoretical work in computational reaction dynamics, especially on the spectra of van der Waals molecules and molecular and atomic collision processes in the gas phase. His work helped shed light on the formation of molecules by ion-molecule reactions at extremely low energies, processes that are important in determining the chemical composition of dark interstellar clouds. He also studied rotational and vibrational energy transfer of polyatomic molecules in molecular beam scattering experiments, and the predissociation states and scattering resonances associated with such reactions. He was an expert in developing clever numerical techniques, such as those involving Green’s operators, to solve the many-dimensional partial differential equations that describe quantum mechanical scattering problems. In addition, he developed a form of the Hamiltonian that was highly useful for understanding the dynamics and distortions of highly excited states of molecules.

His 1966 paper on exact calculations of collinear collisions of particles with harmonic oscillators has been cited nearly 500 times, and he wrote similarly highly cited papers on rotational transitions and energy transfer in scattering, and the potential energy surface of the HeH2 molecule. Over his career, 22 students received PhD degrees under supervision.

He was the husband of the late Masako (nee Fujita) and is survived by his daughter Hideko Rosenzweig and his son David, three grandchildren, and two nieces. He regularly biked several miles a day until 2010, when memory loss made it difficult for him to find his way home. He moved to assisted living in Philadelphia to be near his daughter when it became impossible to live on his own.