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Tom Stephenson

James H. Hammons Chair Emeritus of Chemistry & Provost Emeritus

Senior Research Scholar

Emeritus Chemistry & Biochemistry


  2. Phone: (610) 328-8521
  3. Science Center 186
Thomas Stephenson, James H. Hammons Professor


B.S., Chemistry, Furman University
Ph.D., Physical Chemistry, University of Chicago
Postdoctoral Scholar, Stanford University


The research in my laboratory is focused on understanding the kinetics of important unimolecular reactions in the atmosphere. We are particularly interested in the competition between bimolecular and unimolecular chemistry, and how the relative rates of reaction impact on global models of reactivity in the atmosphere. We use the techniques of high-level electronic structure calculations, combined with master-equation modeling, to deduce both microcanonical and thermal rates of reaction. Our goal is to understand structural, energetic, and thermal effects on unimolecular reactivity in the atmosphere.

Recent Publications

H.K. LeeP. ChantanapongvanijR.R. Schmidt and T.A. Stephenson, “Master Equation Studies of the Unimolecular Decay of Thermalized Methacrolein Oxide: Impact of Atmospheric Conditions,” J. Phys. Chem. A. 127, 4492 (2023).

T.A. Stephenson and M.I. Lester, “Unimolecular Decay Dynamics of Criegee Intermediates: Energy-Resolved Rates, Thermal Rates, and their Atmospheric Impact,” Int. Rev. Phys. Chem., 39, 1 (2020).

J.M. Beames, B.A. O'Donnell, M. Ting, M.I. Lester and T.A. Stephenson, "Experimental Characterization of the Weakly Anisotropic CN X2Σ+ + Ne Potential from IR-UV Double Resonance Studies of the CN-Ne Complex," J. Chem. Phys., 134, 184308 (2011).

J.H. Lehman, J.L. Bertrand*, T.A. Stephenson and M.I. Lester, "Reactive Quenching of OD2Σ+ + by H2: Translational Energy Distributions from Abstraction and Insertion Channels," J. Chem. Phys., 135, 144303 (2011).

J. M. Hutchison, R.R. O'Hern*, T. A. Stephenson, Y. V. Suleimanov and A.A. Buchachenko, "Theoretical and Experimental Studies of Collision-Induced Electronic Energy Transfer from v = 0-3 of the E(0g+) Ion-Pair State of Br2: Collisions with He and Ar", J. Chem. Phys., 128, 184311 (2008).

J.M. Hutchison, B.R. Carlisle* and T.A. Stephenson, "Ro-vibrational Resonance Effects in Collision-Induced Electronic Energy Transfer: I2(E, v = 0-2) + CF4". J. Chem. Phys., 125, 194313 (2006).

I.B. Pollack, Y. Lei, T.A. Stephenson and M.I. Lester, "Electronic Quenching of OH A 2S+ Radicals in Collisions with Molecular Hydrogen". Chem. Phys. Lett., 421, 324 (2006).

I.M. Konen, E.X.J. Li, T.A. Stephenson and M.I. Lester, "Second OH Overtone Excitation and Statistical Dissociation Dynamics of Peroxynitrous Acid". J. Chem. Phys., 123, 204318 (2005).

P.P. Chandra* and T.A. Stephenson, "Franck-Condon Effects in Collision-Induced Electronic Energy Transfer: I2(E; v = 1, 2) + He, Ar". J. Chem. Phys., 121, 2985 (2004).

T.V. Tscherbul, A.A. Buchachenko, M.E. Akopyan, S.A. Poretsky, A.M.Pravilov and T.A. Stephenson, "Collision-Induced Non-Adiabatic Transitions between the Ion-Pair States of Molecular Iodine: A Challenge for Experiment and Theory". Phys. Chem. Chem. Phys., 6, 3201 (2004).