I use statistical mechanics to study systems ranging from the bulk to clusters of just a few atoms. Our goal is to elucidate, through the judicious use of physical models and state-of-the-art calculations, the factors that govern the behavior of these systems. The different areas of my research are described below.
Structure, thermodynamics, and kinetics of combustion generated nanoparticles
Combustion generated nanoparticles are a potential health hazard. These particles are small enough to be inhaled and may catalyze or facilitate the formation of hazardous chemicals such as dioxins. We believe metal oxide nanoparticles are formed during the incineration process and a collaboration with Professors Dellinger, Poliakoff, and McCarley seeks to understand the growth and reaction mechanisms for metal oxide particles. The figure shows some copper oxide clusters currently under examination.
Optimized structures of neutral, positive and negative charged (CuO)n clusters with n=1-5. White atoms are Cu and black atoms are O.
Dynamics and aging of glassy materials
This project studies the diffusion and aging mechanisms in glassy materials ranging from simple monatomic glasses to polymer/flame retardant mixtures. The latter mixtures are used to make computer monitors, among other things. Preventing the diffusion of toxic flame retardants (typically, brominated aromatics) to the surface of the computer monitor is an important practical issue.
Heat capacity as a function of temperature for a monatomic glass for a series of densities. The curves use solid (dashed) lines for temperatures below (above) T*g.
Path Integral Formulation of Quantum Mechanics
We are developing new simulation methods that allow the simultaneous treatment of electronic and geometric degrees of freedom. Such a method will qualitatively improve the efficiency of such simulations. Feynman’s path integral formulation of quantum mechanics is being used in this effort. A new project studies the structure of negatively charged water clusters, investigating where the excess electron is bound to the surface or the interior of the clusters.
Potential energy surface for the N2 molecule, comparing the path integral approach to standard ab initio approaches.
LSU Alumni Association Faculty Excellence Award, 2001
 
Cheri A. McFerrin, Randall W. Hall and Barry Dellinger.  Ab Initio Study of the formation and degradation reactions of chlorinated phenols.  Theochem, 2009, 902, 5-14 
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Randall W. Hall and Peter G. Wolynes.  Intermolecular forces and the glass transition.  J. Phys. Chem. B, 2008, 112, 301-312 
Cheri A. McFerrin, H. Barry Dellinger, and Randall W. Hall.  Ab Initio Study of the Formation and Degradation Reactions of Semiquinone and Phenoxyl Radicals.  Theochem, 2008, 848, 16-23
Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, and Peter G. Wolynes.  Constructing explicit magnetic analogies for the dynamics of glass forming liquids.  Journal of Chemical Physics, 2008, 129, 194505
Feng-Jung Wu, Larry A. Simeral, Anthony A. Mrse, Jan L. Eilertsen, Lacramioara Negureanu, Zhehong Gan, Frank R. Fronczek, Randall W. Hall, and Leslie G. Butler.  Structural Characterization of Al 10 O 6 i Bu16(?-H)2, A High Aluminum-Content Cluster: Further Studies of Methylaluminoxane.  Inorg. Chem., 2007, 46, 4-47
Barry Dellinger, Slawomir Lomnicki, Lavrent Khachatryan, Zofia Maskos, Randall W. Hall, Julien Adounkpe, Cheri McFerrin, Hieu Truong.  Formation of stabilization of persistent free radicals.  Proceedings of the Combustion Institute, 2007, 31, 521-528
Lacramioara Negureanu, Randall W. Hall, Leslie G. Butler, and Larry A. Simeral.  Methylaluminoxane (MAO) polymerization mechanism and kinetic model from ab initio molecular dynamics and electronic structure calculations.  J. Amer. Chem. Soc., 2006, 128, 16816-26
Randall W. Hall.  Simulation of electronic and geometric degrees of freedom using a kink-based path integral formulation: Application to molecular systems.  Journal of Chemical Physics, 2005, 22, 164112:1-8
Yanlong O. Xu, Randall W. Hall, Richard A. Goldstein, and David D. Pollock.  Divergence, recombination, and retention of functionality during protein evolution.  Human Genomics, 2005, 2, 158-167
Jan L. Eilertsen, Randall W. Hall, Larry S. Simeral, Leslie G. Butler.  Tools and Strategies for Processing Diffusion Ordered 2D NMR Spectroscopy (DOSY) of a Broad, Featureless Resonance: An Application to Methylaluminoxane (MAO).  Analytical and Bioanalytical Chemistry, 2004, 378, 1574-1578
P. Bobadova-Parvanova, Y. Oku, A. Wickramasinghe, R. W. Hall and M. G. H. Vicente.  Ab initio and 1H-NMR Study of the Zn(II) Complexes of a nido- and a closo-Carboranylporphyrin.  Journal of Porphyrins and Phthalocyanines, 2004, 8, 996-1006
Pamela L.Bryant, Walter J. Lukiw, Zhehong Gang, Randall W. Hall, and Leslie G. Butler.  High Field 19.6 T 27Al Solid-State MAS NMR of in vitro Aluminated Brain Tissue.  J.Mag. Res., 2004, 170, 257-62
R.W. Hall and P.G. Wolynes.  Microscopic Theory of Network Glasses.  Phys. Rev. Lett., 2003, 90, 085505
Randall W. Hall.  Kink-Based Path Integral Calculations of Atoms He-Ne.  Chem. Phys. Lett., 2002, 362, 549-553
Randall W. Hall.  An Adaptive, Kink-Based Approach to Path Integral Calculations.  J. Chem. Phys., 2002, 116, 1-7
J.A. Gascon, R.W. Hall, C. Ludewigt, and H. Haberland.  Structure of XeN+ clusters (N=3-30): simulation and experiment.  J. Chem. Phys., 2002, 117, 8391-8403
R.W. Hall, L.G. Butler, S. McGuire, S.P. McGlynn, G. Lyon, R. Reese and P. Limbach.  Automated, Web-Based Second-Chance Homework.  J. Chem. Ed., 2001, 78, 1704-1708
Jose A. Gascon and Randall W. Hall.  Spectra and geometries of ArN+ (n = 30-60).  J. Phys. Chem. B, 2001, 105, 6579-6582
Pamela L.Bryant, Chris R. Harwell, Anthony A. Mrse, Earl F. Emery, Zhehong Gan, Tod Caldwell, Arneil P. Reyes, Philip Kuhns, David W. Hoyt, Larry S. Simeral, Randall W. Hall, and Leslie G. Butler.  Structural Characterization of MAO and Related Aluminum Complexes. I. Solid-State 27Al NMR with Comparison to EFG Tensors from ab initio Molecular Orbital Calculations.  J. Amer. Chem. Soc., 2001, 123, 12009-12017
Jose A. Gascon and Randall W. Hall.  Photoabsorption Spectra of Argon Cation Clusters: Monte Carlo Simulations using Many-Body Polarization.  J. Chem. Phys, 2000, 113, 7204-7210
Andrew M. Kolchin and Randall W. Hall.  Electronic Properties of Small Neutral and Charged Beryllium Clusters.  J. Chem. Phys, 2000, 113, 3937-4487
| Former Ph.D. Students |
| Jerome Krough MS,12/00 Cheri McFerrin ,08/07 Yanlong Xu Ph.D,08/06, Partners Health Care Chris Harwell PhD,08/00 Novartis Institutes for Biomedical Research Jose Gascon ,07/02 Assistant Professor, University of Connecticut Lacramioara Negureanu (Lilly) Ph.D,05/06 Melissa Prince PhD,01/95 Andrew Kolchin PhD in Physics,01/00 Postdoc, Quantum Theory Project |
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