Bio

Professor Miller received his B.A. degree in Chemistry at the University of Kansas in 1965, and his Ph.D. degree in Chemistry at Cambridge University in 1968. He worked as a Distinguished Member of the Technical Staff at Bell Telephone Laboratories from 1968 to 1984. He joined the Ohio State University in 1984 as the state of Ohio's first Eminent Scholar. In 1992 he became the chairman of the OSU International Symposium on Molecular Spectroscopy. Professor Miller has received numerous research awards including the William F. Meggars Award (Optical Society of America - 1993), the Bomem-Michaelson Award (Coblentz Society - 1995), the Bourke Medal (Royal Society of Chemistry - 1998), the Broida Prize (American Physical Society- 1999), the Plyler Prize (American Physical Society - 2009), and the Morley Prize (Cleveland Society, American Chemical Society - 2009). Professor Miller is editor-in-chief of the Journal of Molecular Spectroscopy. He has served or serves on the following journal editorial boards: Journal of Chemical Physics; Review of Scientific Instruments; Journal of Physical Chemistry; Journal of the Optical Society of America; Chemtracts; Contributing Editor; Annual Reviews of Physical Chemistry; Journal of Molecular Spectroscopy; Laser Chemistry; Journal of Molecular Structure; and Chemical Physics Letters. Professor Miller is a Fellow of the Optical Society of America, American Physical Society, American Chemical Society, American Association for Advancement of Science, and Society for Applied Spectroscopy. 

Research Overview

My research has long centered on the spectroscopic detection and characterization of reactive chemical intermediates. These molecules play critical roles in a variety of processes of significant importance to our society and economy, examples of which include combustion, atmospheric and interstellar chemistry, plasmas and reacting flows. For many years my research group performed both experimental and theoretical/computational spectroscopy. Recently, my group has focused on theoretical/computational work only. However, we maintain active collaborations with experimental groups in Engineering at Ohio State and Chemistry at the University of Louisville as well as a strong collaboration with a theoretical group, highly skilled in electronic structure calculations, at the University of Florida.

Recent analytical work in my group has involved the simulation of observed, cavity-ring-down (CRD), electronic-absorption spectra of metastable, triplet N₂ molecules. These simulations allow the determination of triplet N₂ concentrations that are critical to the understanding of the kinetics of electrical discharges, atmospheric shock waves, and various non-equilibrium reacting flows. Another area of interest is the CRD spectroscopy of alkoxy radicals, RO• with R an alkyl group. These radicals are key reaction intermediates in both the combustion of fossil fuels and the degradation of organic molecules in the atmosphere. This work involves assigning the experimentally observed fine structure in electronic spectra that is caused by vibrational and rotational motion of the nuclei. To perform these assignments, we make extensive use of predictions that are based on quantum chemistry calculations of the electronic structure of the alkoxy radicals.

We also investigate theoretically the fundamental basis for chemical reactivity. Much of the foundation for molecular quantum mechanics, particularly electronic-structure calculation, rests on the Born-Oppenheimer approximation (BOA), which states that light electrons move so fast that we can calculate the electronic properties of molecules, while considering the heavy nuclei to be stationary. However the BOA must fail when chemical bonds are made or broken, since those processes require movement by both electrons and nuclei. Therefore it is important to understand the coupling of electronic and nuclear motion that plays a significant role in areas that range from molecular dynamics to electronic spectroscopy. We develop models and test them by predicting the spectra of molecules that do not obey the BOA, typically because of Jahn-Teller effects due to the fact that they are reactive, open-shell, polyatomic molecules in degenerate electron states.

Former members of the Miller group now hold faculty positions at Texas A&M University, University of Utah, Wright State University, University of Leicester, Mississippi State University, Emory University, Academia Sinica, University of Pennsylvania, Howard University, Eotvos University, University of Nottingham, Beijing Normal University; research positions in the national labs at Wright-Patterson Airforce Base, Applied Physics Lab at Johns Hopkins, Brookhaven National Lab; and industrial research positions at ExxonMobil, KLA-Tencor, Daylight Solutions, Innovative Scientific Solutions, General Electric.

Professor Miller welcomes inquiries regarding openings in his group.

Recent Publications

A complete list of all publications can be found here.

E. Jans; I. W. Jones, X. Yang, T. A. Miller, J. F. Stanton, & I. V. Adamovich, Time-Resolved Measurements of HO₂ Radical in a Heated Plasma Flow Reactor Combust. Flame, 2022, 241, 112097

Electronic spectroscopy of the transitions of jet-cooled calcium ethoxide radicals: Vibronic structure of alkaline earth monoalkoxide radicals of Cs symmetry, A. C. Paul, K. Sharma, H. Telfah, T. A. Miller, & J. Liu, J. Chem. Phys., 2021, 155, 024301

Vibronically coupled states: computational considerations and characterisation of vibronic and rovibronic spectroscopic parameters, K. Sharma, T. A. Miller & J. F. Stanton, Int. Rev. Phys. Chem., Taylor & Francis, 2021, 40, 165-298

"Rotational and fine structure of open-shell molecules in nearly degenerate electronic states. II. Interpretation of experimentally determined interstate coupling parameters of alkoxy radicals," Y. Yan, K. Sharma, T. A. Miller, and J. Liu J. Chem. Phys. 153 174306 (2020).

"Time-Resolved Populations of N₂(A³ Σ _u⁺,v) in Nanosecond Pulse Discharge Plasmas," E. R. Jans, K. Frederickson, T. A. Miller, and I. V. Adamovich J. Mol. Spectros. 365 111205 (2019).

"First-Principles Calculation of Jahn-Teller Rotational Distortion Parameters," K. Sharma, Scott Garner, T. A. Miller, and J. F. Stanton J. Phys. Chem.A 123 4990-5004 (2019).

"Quantifying the Effects of Higher Order Jahn-Teller Coupling Terms on Fits Using a Second Order Jahn-Teller Hamiltonian," H. K. Tran, J. F. Stanton, and T. A. Miller, J. Mol. Spectros. 343, 102-115 (2018).

"Manifestations of Torsion-CH Stretch Coupling in the Infrared Spectrum of CH₃OO," K.-H. Hsu, Y.-H. Huang, Y.-P. Lee, M. Huang, T. A. Miller, and A. B. McCoy J. Phys Chem. A. 120, 4827-4837 (2016).

"Laser-Induced Fluorescence Spectroscopy of Jet-Cooled t-Butoxy," J. Liu, N. J. Reilly, A. Mason and T. A. Miller, J. Phys. Chem. A. 119, 11804-11812 (2015).

"Jet Cooled Cavity Ringdown Spectroscopy of the ²E"<_-²A'₂ Transition of the NO₃ Radical; T. Codd, M.-W. Chen, M. Roudjane, J. F. Stanton and T. A. Miller, J. Chem. Phys. 142, 184305, (2015).

"Rotationally Resolved <_- Electronic Spectra of the Isopropoxy Radical: A Comparative Study," J. Liu, D. Melnik and T. A. Miller, J. Chem. Phys. 139, 094308, (2013).

"The Electronic Transition Moment for the 0⁰₀ Band of the _- Transition in the Ethyl Peroxy Radical," D. Melnik, P. S. Thomas and T. A. Miller, J. Phys. Chem. A 115, 13931 (2011).

"Measurements of the absolute absorption cross sections of the <_- Transition in organic peroxy radicals by dual wavelength cavity-ringdown spectroscopy," D. Melnik, R. Chhantyal-Pun, and T. A. Miller J. Phys. Chem. A, 114, 11583 (2010)