Timothy Lee

Contact Information
Title: 
Chief
Phone: 
(650)604-5208
Email : 
Timothy.J.Lee@nasa.gov
Other Affiliation: 
Professional Background
Professional Biography: 
Division Chief, Space Science and Astrobiology Division, March 2007 to present
Branch Chief, Astrophysics Branch, NASA Ames, July 2005 to March 2007
Research Scientist, NASA Ames Research Center, Feb. 1989 to present
Research Scientist, ELORET Inst., NASA Ames Research Center, Sept. 1988 to Jan. 1989
NATO Postdoctoral Fellow, University of Cambridge, England, Sept. 1987 to Aug. 1988
Tutor, Jesus College, Cambridge, England, Sept. 1987 to Jan. 1988
Postdoctoral Associate, University of Cambridge, England, Jan. 1987 to Aug. 1987


Professional Activities:
Editor of Molecular Astrophysics, March 2015 to present.
Co-Guest Editor for the Nicholas C. Handy memorial issue of Molecular Physics, July, 2015.
Member, Editorial Advisory Board of the Journal of Physical Chemistry, January 2014 to present.
Chair, Astrochemistry Subdivision of the Physical Chemistry Division of the American Chemical Society, September 2015 to August 2016
Chair-Elect, Astrochemistry Subdivision of the Physical Chemistry Division of the American Chemical Society, September 2014 to August 2015
Vice-Chair, Astrochemistry Subdivision of the Physical Chemistry Division of the American Chemical Society, September 2013 to August 2014
Member of the International Advisory Committee for the LASSIE ITN, 2010 to present.
Member of the International Advisory Committee for the Dutch Astrochemistry Network, 2010 to present.
Co-organizer of Workshop Astrochemistry: Molecular Networks connecting the Universe, sponsored by the Dutch NSF (NWO), Amsterdam, April 2011.
Co-organizer of a symposium, Chemical Studies Important to Astrobiology, for the Physical Chemistry Division of the ACS, Boston, August, 2002.
Editor of Spectrochimica Acta, Part A, January 1999 through 2006.
Member, Editorial Board of Molecular Physics, January 1998 to December 2002.
Member, Editorial Advisory Board of Spectrochimica Acta, Part A, July, 1997 to December, 1998.
Senior Editor of Asian Journal of Spectroscopy, February, 1997 to December, 1998.
Co-Guest Editor for a special issue of Spectrochimica Acta, Part A entitled Theoretical Spectroscopy: State of the Science, March, 1999.
Co-Guest Editor for the Bowen Liu memorial issue of Molecular Physics, February, 1999.
Guest Editor for a special issue of Spectrochimica Acta, Part A entitled Ab Initio and Ab Initio Derived Force Fields: State of the Science, July, 1997.
Co-organizer of the 1991 West Coast Theoretical Chemistry Conference, NASA Ames.
Co-organizer of the 1989 West Coast Theoretical Chemistry Conference, IBM Almaden.


Education: 
Ph.D., Physical (Theoretical) Chemistry, University of California, Berkeley, 1986
B.Sc., Chemistry with High Scholastic Honor, Colorado School of Mines, 1982


Research Interests: 
My training is in electronic structure theory and I have extensive experience in both the development of theoretical methods, and the application of these to fundamental problems of interest to various parts of NASA. Currently, most of my work is in the application of electronic structure methods to three areas: 1) the calculation of highly accurate rovibrational spectra of small molecules of interest to astronomy and astrophysics, such as the ammonia, CCH-, NH2-, and HO2+ molecules; 2) the calculation of the vertical electronic absorption or emission process in polycyclic aromatic hydrocarbons (PAHs), neutrals, cations, anions, and other derivatives, such as nitrogen substituted PAHs (PANHs), or PAH clusters; and 3) the investigation of the properties of molecules of interest in atmospheres (including Earth) such as chemical stability, thermal stability, spectroscopy (both rovibrational and electronic), Ozone Depletion Potentials (ODPs), Global Warming Potentials (GWPs), etc.

Past applications work has included investigating the properties of high-energy density materials that could be used as novel rocket fuels, such as Td N4, examining chemical reaction pathways, such as the destruction of chlorine nitrate on the surface of polar stratospheric clouds, the reaction of F + H2, or novel organic reactions (e.g., the Bergman reaction), many investigations of the rovibrational or electronic spectroscopy of novel molecules or ions, mostly in the gas-phase but also including magnesium, sulfate salts of interest to Europa, and many investigations generally determining the properties of gas-phase molecules and ions of interest in atmospheres, the interstellar medium, or other exotic environments.

Work on theoretical methods has included the development and efficient implementation (on both vector and massively parallel supercomputers) of sophisticated ab initio electron correlation methods with particular emphasis on perturbation and coupled-cluster theories. An elegant piece of work involved the formulation and implementation of efficient open-shell perturbation and coupled-cluster theories based on the use of ``symmetric spin-orbitals.'' I have extensive experience with development of analytical derivative methods applied to electron correlation approaches, and also with development of reliable diagnostics that can be used to asses the expected accuracy from a given calculation/method, such as the T1 diagnostic used in coupled-cluster theory. More recent efforts have been aimed at developing novel and accurate methods for the study of excited electronic states, and at developing a scalable coupled-cluster method by approximating certain integrals in order to reduce the amount of data necessary to perform the coupled-cluster calculation.

Select Publications: 
X. Huang, D. W. Schwenke, and T. J. Lee, “Rovibrational Spectra of Ammonia. Part I: Unprecedented Accuracy of a Potential Energy Surface used with Nonadiabatic Corrections,” J. Chem. Phys. 134, 044320 (2011).

X. Huang, D. W. Schwenke, and T. J. Lee, “Rovibrational Spectra of Ammonia. Part II: Detailed Analysis, Comparison, and Prediction of Spectroscopic Assignments for 14NH3,15NH3, and 14ND3,” J. Chem. Phys. 134, 044321 (2011).

X. Huang, D. W. Schwenke, S. A. Tashkun, and T. J. Lee, “An Isotopic-Independent Highly-Accurate Potential Energy Surface for CO2 Isotopologues and Primitive 12C16O2 IR Line lists,” J. Chem. Phys. 136, 124311 (2012).

K. Sung, L. R. Brown, X. Huang, D. W. Schwenke, T. J. Lee, S. L. Coy, and K. K. Lehmann, “Extended line positions, intensities, empirical lower state energies, and quantum assignments of NH3 from 6300 to 7100 cm-1,” J. Quant. Spectrosc. Radiat. Transfer. 113, 1066 (2012).

R. C. Fortenberry, X. Huang, A. Yachmenev, W. Thiel, and T. J. Lee, “On the Use of Quartic Force Fields in Variational Calculations,” Chem. Phys. Lett. 574, 1 (2013). (CPL Frontiers Article)

C. J. Mackie, A. Candian, X. Huang, T. J. Lee, and A. G. G. M. Tielens, “Linear Transformation of Anharmonic Molecular Force Constants between Normal and Cartesian Coordinates,” J. Chem. Phys. 142, 244107 (2015).

R. C. Fortenberry, T. J. Lee, and H. S. P. Müller, “Excited Vibrational Level Rotational Constants for SiC2: A Sensitive Molecular Diagnostic for Astrophysical Conditions,” Molecular Astrophysics 1, 13 (2015).

E. Maltseva, A. Petrignani, A. Candian, C. Mackie, X. Huang, T. J. Lee, A. G. G. M. Tielens, J. Oomens, and W. J. Buma, “High-resolution IR absorption spectroscopy of polycyclic aromatic hydrocarbons: the realm of anharmonicity,” Astrophys. J. 814, 23 (2015); Erratum: Astrophys. J. 820, 81 (2016).

P. P. Bera, M. Nuevo, C. K. Materese, S. A. Sandford, and T. J. Lee, “Mechanism for the Formation of Thymine under Astrophysical Conditions, and its Role in the Origin of Life,” J. Chem. Phys. 144, 144308 (2016).

T. Helgaker, P. J. Knowles, T. J. Lee, J. E. Rice, and D. J. Tozer, “Foreward” for the Molecular Physics Special Issue in Honour of Professor N. C. Handy, Mol. Phys. 113, 1509 (2015).

R. C. Fortenberry, Q. Yu, J. S. Mancini, J. M. Bowman, T. J. Lee, T. D. Crawford, W. F. Klemperer, and J. S. Francisco, “Spectroscopic Consequences of Proton Delocalization in OCHCO+,” J. Chem. Phys. 143, 071102 (2015).

C. J. Mackie, A. Candian, X. Huang, E. Maltseva, A. Petrignani, J. Oomens, W. J. Buma, T. J. Lee, and A. G. G. M. Tielens, “The anharmonic quartic force field infrared spectra of three polycyclic aromatic hydrocarbons: naphthalene, anthracene, and tetracene,” J. Chem. Phys. 143, 224314 (2015).

D. S. N. Parker, T. Yang, B. B. Dangi, R. I. Kaiser, P. P. Bera, and T. J. Lee, “Low Temperature Formation of Nitrogen-Substituted Polycyclic Aromatic Hydrocarbons (PANHs)-Barrierless Routes to Dihydro(iso)quinolines,” Astrophys. J. 815, 115 (2015).

Q. Yu, J. M. Bowman, R. C. Fortenberry, J. S. Mancini, T. J. Lee, T. D. Crawford, W. Klemperer, and J. S. Francisco, “The Structure, Anharmonic Vibrational Frequencies, and Intensities of NNHNN+,” J. Phys. Chem. A 119, 11623 (2015).

M. L. Theis, A. Candian, A. G. G. M. Tielens, T. J. Lee, and R. C. Fortenberry, “Electronically Excited States of Anistropically Extended Singly-Deprotonated PAH Anions,” J. Phys. Chem. A 119, 13048 (2015).

S. I. L. Kokkila Schumacher, P. P. Bera, and T. J. Lee, “Characterization of the Azirinyl Cation and its Isomers,” J. Phys. Chem. A 120, 1275 (2016).

R. C. Fortenberry, J. S. Francisco, and T. J. Lee, “Towards the Astronomical Detection of the Proton-Bound Complex NN-HCO+: Implications for the Spectra of Protoplanetary Disks,” Astrophys. J. 819, 141 (2016).

D. S. Underwood, J. Tennyson, S. N. Yurchenko, X. Huang, D. W. Schwenke, T. J. Lee, S. Clausen, and A. Fateev, “ExoMol molecular line lists – XIV: The rotation-vibration spectrum of hot SO2,” MNRAS 459, 3890 (2016).

R. C. Fortenberry, E. Roueff, and T. J. Lee, “Inclusion of 13C and D in Protonated Acetylene,” Chem. Phys. Lett. 650, 126 (2016).
Curriculum Vita: 
Other Information
Awards and Other: 
Hirsch index (h-index) of 57 according to Web of Science data
Paul A.M. Dirac Medal, 1998; awarded by the World Association of Theoretical and
Computational Chemists
Elected a Fellow of the American Association for the Advancement of Science, 2005
Elected a Fellow of the American Physical Society, 2001
NASA Exceptional Scientific Achievement Medal, 2011
NASA Exceptional Scientific Achievement Medal, 1998
NASA Ames Associate Fellow, 1997
Listed among the 400 most cited chemists in the world for the period 1981 to June, 1997 in a
compilation by the Institute for Scientific Information.
NASA Group Achievement Award (Ames Workforce Realignment Team), 2007
NASA Group Achievement Award (Project Columbia Team), 2005
NASA Group Achievement Award (Devices and Nanotechnology), 2000
Outstanding Graduating Chemist, Colorado School of Mines, 1982
Lando Summer Research Fellowship at the University of Minnesota, 1981
American Chemical Society High School Chemistry Award, 1978