Samuel B. Trickey

Personal Information
  • Professor of Physics and Chemistry (emeritus June 2005)
  • Former Director QTP (1999-2004)
  • Email address: trickey@qtp.ufl.edu
  • Office: 2324 New Physics Building
  • Phone: 352-392-1597
  • Fax: 352-392-8722

Research Interests

Predictive Calculation of
  • structures and properties of Ultra-thin Films and counterpart crystals, with emphasis on surface effects related to chemical bonding in cracking, quantum size effects, energy deposition by charged particles, and high magnetic field effects.
  • high-pressure and/or high-magnetic field behavior of solids, with emphasis on structural phase transitions and energy deposition properties, as well as calibration of embedding potentials for Molecular Dynamics in multi-scale simulations.
Current computational effort is on SiO2 crystals, ultra-thin films, and intercalated with model layers of reactants relevant to cracking. The objective is to provide information on energetics and reactivity indices (e.g., local hardness) for refining the potentials used in molecular dynamics.  This work is funded under the NSF ITR-medium "Science and Software for Predictive Simulation of Chemo-mechanical Phenomena in Real Materials", R.J. Barlett PI, H-P. Cheng, and S.B. Trickey co-PIs (DMR-0325553). 

The work on energy deposition in thin films and crystals was primarily in collaboration with Prof. J.R. Sabin (also of QTP) and former postdoctoral associate, Richard J. Mathar. Now mostly published, we focused on all-electron first-principles calculation of the full RPA microscopic dielectric function and associated stopping cross-section. 

Development of Algorithms for Predictive Simulations of Materials

Methods for detailed DFT calculations on materials are developed in close collaboration with Dr. Jonathan Boettger (X7, Los Alamos National Lab), the principal author of the code GTOFF (that originated here). A recent review article is listed below.
Algorithmic work recently has been a massive rework of GTOFF in modern C++; see abstract by J. Ashley Alford at the March 2005 APS meeting. This effort is funded under the NSF ITR-small project DMR-0218957.

Under the ITR-medium cited above, Juan Torras Costa, Erik Deumens, and I are developing PUPIL (Program for User Package Interfacing and Linking), a JAVA, CORBA, and XML-based system for interoperating user application packages (e.g. electronic structure, molecular dynamics, domain identifiers) as a systematic multi-scale modeling tool.

Density Functional Theory (DFT)

I work on both time-dependent and time-independent DFT, and more recently, on Current DFT (CDFT).

Wuming Zhu (Ph.D. August 2005) and I have done an exhaustive study of CDFT and ordinary DFT in large external B fields, including exact Hooke's atom solutions. See the Phys. Rev. A paper cited below and more to come. This is under the ITR-small cited above.

Prof. Brian Weiner (Penn State) and I have developed a new, constructive (rather than existence-theorem) approach to the constrained search method based on properties of transformations on fiber bundles.  It enables a systematic parameterization of the time-dependent variational principle.  Currently we are developing computationally practical approximate functionals.  In the time-independent case, the emphasis of that development is improved approximations for non-collinear magnetism via general spin orbitals and the Fukutome classification we introduced some years back.

Valentin Karasiev (IVIC, Venezuela), Frank Harris (Utah), and I are developing orbital-free approximations to the Kohn-Sham kinetic energy to use in calculating Born-Oppenheimer forces in fast molecular dynamics simulations. This work is part of the ITR-medium cited above.

Representative Publications

  • Analytical Solutions for Two Electrons in an Oscillator Potential and a Magnetic Field,, Wuming Zhu and S. B.Trickey, Phys. Rev. A 72, 022501 [1-5] (2005).
  • Density Functional Energetics of alpha-Quartz for Calibration of SiO2 Interatomic Potentials, N. Flocke, Wuming Zhu, and S. B. Trickey, J. Phys. Chem. B 109, 4168-71 (2005).
  • Deformation and Fracture of SiO2 Nanorod, Ting Zhu, Ju Li, Sidney Yip, R. J. Bartlett, S. B. Trickey, and N. H. de Leeuw, Molecular Simulations 29, 671-76 (2003).
  • Methods and Implementation of Robust, High-precision Gaussian Basis DFT Calculations for Periodic Systems: the GTOFF Code, S. B. Trickey, J. A. Alford, and J. C. Boettger, in Computational Materials Science, vol. 15 of "Theoretical and Computational Chemistry", J.Leszczynski ed. (Elsevier, Amsterdam, 2004)) 171-228.
  • A Critical Assessment of Density Functional Theory with Regard to Applications in Organometallic Chemistry, A. Goerling, S. B. Trickey, P. Gisdakis, and N. Roesch, in Topics in Organometallic Chemistry, vol. 4, P. Hofmann and J. M. Brown, Eds. (Springer Verlag, Heidelberg, 1999) 109-63.
  • State Energy Functionals and Variational Equations in Density Functional Theory, B. Weiner and S. B. Trickey, J. Molec. Struct. (Theochem) 501-02, 65-83 (2000).
  • Inclusion of Relativistic Effects in Gaussian-basis Density Functional Calculations for Extended Systems, J. C. Boettger and S. B. Trickey, J. Molec. Struct. (Theochem) 501-02, 285-96 (2000).
Click here for a more extensive list of Publications.

Recent Invited Lectures

  • Approximate Density Functionals for Molecular Dynamics Simulations of Material Properties, Fifth Congress of Internat. Soc. for Theoretical Chemical Physics, New Orleans LA, 25 July 2005
  • Prediction of Materials Properties Via Gaussian Orbital DFT Methods, 13th International Conference on Current Trends in Computational Chemistry, Jackson MS, 12 Nov. 2004.
  • First Principles Electronic Structure Methods and the Prediction of Materials Properties, XXIV Congreso Anual, Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales, Rivera Maya, Mexico, Sept. 29, 2004.
  • Large-scale, Grid-enabled Gaussian Orbital Implementation of Current Density and Spin Density Functional Theory for Ordered Systems, NSF DMR Computational Materials Theory Review meeting, Univ. of Illinois, Urbana-Champaign, June 17, 2004.

Chile Click here for recent visit to Chile.
Click for March 25,2003, Physics Dept. Presentation:  Opportunities in Computationally Oriented Materials Theory
Here's the link to National Farm Worker Ministry, a long-time personal commitment.
Here's the link to the Gainesville sailing club
Here's a link to an interesting houseboat (not my usual interest in boats)

Last modified 15 December 2005