Katharine Hunt
University Distinguished Professor Office: 17 A Chemistry
Phone: 517-355-9715 266 /
Websites: Research Group - Area
Awards & Honors
Genealogy/Graduates
Nonlocal Electromagnetic Response/Nonequilibrium Thermodynamics
(Research Description PDF - 0 kb)Quantum mechanical research in my group focuses on the response of molecules to applied electric and magnetic fields. The work encompasses density functional theory, dielectric theory for nanoscale species, and optical trapping of single molecules. Our research in statistical mechanics focuses on interrelating thermodynamic and stochastic descriptions of nonequilibrium systems.
Recently, I have derived the electronic energy of a molecule as a functional of the density and the change in the charge density in the presence of a perturbing potential. The result is a simple, closed functional, which is exact within the nonrelativistic, Born-Oppenheimer approximation. In collaboration with Professor Piotr Piecuch and members of his research group, Ruth Lafuente and I are working to evaluate electronic energies using this functional, along with accurate values of the charge-density susceptibility.
Dr. Olga Jenkins and I have developed a quantum mechanically rigorous form of dielectric theory that applies to nanoscale objects. Intermolecular forces calculated from this theory are identical to those obtained from standard perturbation theory. Our analysis yields the dielectric screening function within a molecule, in a nonlocal form.
Professor Jim Harrison, Dr. Xiaoping Li, and I have carried out ab initio calculations of the collision-induced polarizability of hydrogen molecule pairs. Professor Lothar Frommhold's group at the University of Texas at Austin has found excellent agreement between the roto-translational Raman spectra predicted from our theoretical results and the experimental spectra. Ms. Dorothy Gearhart is currently working on line shapes for far IR absorption by nitrogen/methane mixtures, where a substantial discrepancy remains between experiment and theory.
My research group is also working to develop a quantitative model for optical trapping of DNA fragments or proteins labeled with fluorescent dyes. Optical trapping results from the interaction between the laser electric field and the polarization induced in biomolecules by the laser field. We are developing new models for the trapping potential, taking into account the intramolecular distribution of the induced polarization.
In a separate area of research, in collaboration with Professor John Ross at Stanford University and Professor Paul Hunt (MSU), we have developed a thermodynamic and stochastic theory of non-equilibrium systems. We are applying it to determine the deviations from the Nernst potential for electrochemical systems that contain multiple, disequilibrated redox couples, in a flow tank
Selected Publications
A nonlocal energy functional derived from the fluctuation-dissipation theorem, Katharine L. C. Hunt, ACS Symposium Series, Electron Correlation Methodology, edited by Angela K. Wilson and Kirk A. Peterson, 2007, 958, 169.Derivatives of the polarization propagator including orbital relaxation effects, Edmund L. Tisko and Katharine L. C. Hunt, J. Chem. Phys. 2007, 126, 204105.
The collision-induced polarizability of a pair of hydrogen molecules, X. Li, C. Ahuja, J. F. Harrison, and K. L. C. Hunt, J. Chem. Phys. 2007, 126, 214302.
The geometry, vibrational frequencies, thermochemistry, quadrupole moments and electronic structure of C2Na2 : Comparison with C2Li2 , C2H2 , C2F2 and C2Cl2 , Dorothy J. Gearhart, Katharine L. C. Hunt, and James F. Harrison, J. Mol. Struct. THEOCHEM 2008, 858, 31.
