Phillip Thomas

Phillip S. Thomas Ph. D.

HPC Performance Engineer

Application Performance Group

Biographical Sketch

Phillip is an Application Performance Engineer at NERSC. His areas of expertise include Fortran, GPU programming, and algorithms related to tackling the Curse of Dimensionality. His efforts at NERSC involve improving the performance of material science applications. He currently works in the BerkeleyGW project developing a GPU implementation for StochasticGW, a code for computing excited states of very large material systems.

Before coming to NERSC, Phillip developed compute kernels for Wave Computing in Santa Clara, California. Prior to that Phillip worked as a post-doctoral researcher in quantum reaction dynamics at Queen's University in Ontario, Canada, and at Leiden University in the Netherlands. He also has experience in experimental molecular spectroscopy from a post-doctoral fellowship at The Ohio State University. Phillip's Ph. D. thesis topic was spectroscopy and simulation of reactive organic molecules.

Education

Ph.D., Physical Chemistry, University of Wisconsin - Madison
B.S., Chemistry, Wingate University

Publications

“Using an Iterative Eigensolver and Intertwined Rank Reduction to Compute Vibrational Spectra of Molecules with More Than a Dozen Atoms: Uracil and Naphthalene.” Phillip S. Thomas, Tucker Carrington, Jay Agarwal, and Henry F. Schaefer. J. Chem. Phys., 2018, 149, 064108.
“An Intertwined Method for Making Low-Rank, Sum-of-Product Basis Functions That Makes It Possible to Compute Vibrational Spectra of Molecules with More Than 10 Atoms.” Phillip S. Thomas and Tucker Carrington. J. Chem. Phys., 2017, 146, 204110.
“Comparison of Different Eigensolvers for Calculating Vibrational Spectra Using Low-Rank, Sum-of-Product Basis Functions.” Arnaud Leclerc, Phillip S. Thomas, and Tucker Carrington. Mol. Phys., 2017, 115, 1740-1749.
“Rotational Effects on the Dissociation Dynamics of CHD₃ on Pt(111).” Gernot Füchsel, Phillip S. Thomas, Jurriaan den Uyl, Yesim Öztürk, Francesco Nattino, Hans-Dieter Meyer, and Geert-Jan Kroes. Phys. Chem. Chem. Phys., 2016, 18, 8174-8185.
“Using Nested Contractions and a Hierarchical Tensor Format to Compute Vibrational Spectra of Molecules with Seven Atoms.” Phillip S. Thomas and Tucker Carrington. J. Phys. Chem. A, 2015, 119(52), 13074-13091.
“Chebyshev High-Dimensional Model Representation (Chebyshev-HDMR) Potentials: Application to Reactive Scattering of H₂ from Pt(111) and Cu(111) Surfaces.” Phillip S. Thomas, Mark F. Somers, Anne W. Hoekstra, and Geert-Jan Kroes. Phys. Chem. Chem. Phys., 2012, 14, 8268-8643.
“Electronic Transition Moment for the 0₀⁰ Band of the A—X Electronic Transition in the Ethyl Peroxy Radical” Dmitry Melnik, Phillip S. Thomas, and Terry A. Miller. J. Phys. Chem. A,2011, 115, 13931-13941.
“The A−X Electronic Absorption of Cyclopentadienyl Peroxy Radical (c-C₅H₅OO∙): A Cavity Ringdown Spectroscopic and Computational Study.” Phillip S. Thomas and Terry A. Miller. Chem. Phys. Lett., 2011, 514, 196-201.
“A−X Absorption of Propargyl Peroxy Radical (H−C≡C−CH₂OO·): A Cavity Ring-Down Spectroscopic and Computational Study.” Phillip S. Thomas, Neal D. Kline, and Terry A. Miller. J. Phys. Chem. A,2010, 114, 12437-12446.
“Dialkynyl Carbene Derivatives: Generation and Characterization of Triplet tert-Butylpentadiynylidene (t-Bu−C≡C−C−C≡C−H) and Dimethylpentadiynylidene (Me−C≡C−C−C≡C−Me).” Phillip S. Thomas, Nathan P. Bowling, Nicola J. Burrmann, and Robert J. McMahon. J. Org. Chem.,2010, 75(19), 6372-6381.
“Observation of the A—X Electronic Transition of the β-Hydroxyethylperoxy Radical.” Rabi Chhantyal-Pun, Neal D. Kline, Phillip S. Thomas, and Terry A. Miller. J. Phys. Chem. Lett.,2010, 1, 1846-1852.
“Cavity Ringdown Spectroscopy of the NIR A—X Electronic Transition of Allyl Peroxy Radical (H₂C=CH−CH₂OO·).” Phillip S. Thomas and Terry A. Miller. Chem. Phys. Lett., 2010, 491, 123-131.
"The A—X Absorption of Vinoxy Radical Revisited: Normal and Herzberg-Teller Bands Observed via Cavity Ringdown Spectroscopy.” Phillip S. Thomas, Rabi Chhantyal-Pun, Neal D. Kline, and Terry A. Miller. J. Chem. Phys., 2010, 132, 114302.
“Observation of the A—X Electronic Transitions of Cyclopentyl and Cyclohexyl Peroxy Radicals via Cavity Ringdown Spectroscopy.” Phillip S. Thomas, Rabi Chhantyal-Pun, and Terry A. Miller. J. Phys. Chem. A,2010, 114, 218-231.
“Spectroscopy and Photochemistry of Triplet Methylpentadiynylidene (Me−C≡C−C−C≡C−H).” Phillip S. Thomas, Nathan P. Bowling, and Robert J. McMahon. J. Am. Chem. Soc.,2009, 131, 8649-8659.
“Reactive Carbon-Chain Molecules: Synthesis of 1-Diazo-2,4-Pentadiyne and Spectroscopic Characterization of Triplet Pentadiynylidene (H−C≡C−C−C≡C−H).” Nathan P. Bowling, Robert J. Halter, Jonathan A. Hodges, Randal A. Seburg, Phillip S. Thomas, Christopher S. Simmons, John F. Stanton, and Robert J. McMahon. J. Am. Chem. Soc.,2006, 128, 3291-3302.
“Green Heterocycle Synthesis, Isochromenones, Artemidin.” T.A. Bryson, J.J. Stewart, J.M. Gibson, P.S. Thomas, and J.K. Berch. Green Chem., 2003, 5, 174-176.
“Benzene-Free Synthesis of Phenol.” James M. Gibson, Phillip S. Thomas, Joshua D. Thomas, Jessica L. Barker, Sunil S. Chandran, Mason K. Harrup, Karen M. Drafts, and John W. Frost. Angew. Chem. Int. Ed., 2001, 40(10), 1945-1948.