University of Pittsburgh

Rob Coalson

Contact Info:

Department of Chemistry
Chevron Science Center
219 Parkman Avenue
Pittsburgh, PA 15260

Office: 321 EBERL
Phone: 412-624-8261

Professor

Theory of Chemical Dynamics

Quantum Dynamics Theory, with Application to Condensed Phase Systems

Exact and approximate wavepacket dynamics techniques, developed in our group and elsewhere, have been utilized to investigate experimentally observable signatures of condensed ph ase quantum dynamics. Specific processes include resonance Raman spectra of chromophores (e.g. CS2) in solvents of various polarities, electron transfer of mixed valences transition metal complexes in polar solvents and e lectron stimulated desorption of adsorbates from solid surfaces. [(e.g., CO on Cu]. Theoretical issues include development of (i) numerical algorithms capable of solving the many-body time-dependent Schrodinger Equation, (ii) implementable formalism for extracting spectroscopic observables from condensed phase wavepacket simulations, and (iii) simple models (e.g., of a single particle interacting with an environment) to aid in the interpretation of experimental and simulation data. Frontiers include (i) quantum dynamics of systems immersed in liquids and other amorphous environments, (ii) determination of Born-Oppenheimer level electronic structure "on the fly" in the course of during nuclear wavepacket dynamical evolution, (iii) accurate treatment of ele ctronuclear coupling effects, for example, in nondiabatic transition processes, and (iv) understanding the effect of applied laser fields on electron transfer reactions. 

Colloid Science: Structural and Dynamics of Charged Polystyrene Sphere Suspensions

We are interested in the properties of highly charged polystyrene spheres (diameter ca. 0.1 micron) suspended in aqueous ionic solutions. To minimize Coulombic rep ulsions, these polyballs can order into a solid phase; melting is caused by addition of a sufficient quantity of impurity ions that shield the polyballs. Current work centers around quantification of the fundamental inter-polyball forces as a function of impurity ion concentration, polyball charge, etc. Also underway are studies of the structure and stability of novel polyball structures (including materials made by embedding colloid crystals in polymer films and gels), and investigation of nonequilibrium dynamics of these suspensions (e.g., response to laser heating and shearing)  

Design of Dielectric Waveguides

Design of Dielectric Waveguides. Interest in electro-optic integration of GaAs derived materials has spurred characterization of the field-induced optical properties of multi-quantum well structures. We compute numerical solutions to Maxwellís Equations in order to predict the characteristics of optical waveguides made from such structures. Recently, we have applied optimal central theory to aid in the design of these and other optical waveguides. Also of interest are a microscopic understanding of optical absorption and electrical conduction processes in these materials and the influence of such microscopic properties on the macroscopic electromagnetic fields that propagate through waveguides.

Awards

  • NSF Presidential Young Investigator, 1986-91

  • Alfred P. Sloan Foundation Fellow, 1989-91

  • Camille and Henry Dreyfus Teacher-Scholar, 1990-94

  • Chancellor's Distinguished Research Award, University of Pittsburgh, 1995

Publications

Morphology of Polymer Brushes Infiltrated by Attractive Nanoinclusions of Various Sizes,” Opferman, MG, Coalson, RD, Jasnow, D, Zilman, A , LANGMUIR, Vol. 29, 2013, Pages 8584-8591, http://www.ncbi.nlm.nih.gov/pubmed/23758614
Langevin Dynamics Simulation of 3D Colloidal Crystal Vacancies and Phase Transitions,” R. Laghaei, S.A. Asher and R.D. Coalson, Journal of Physical Chemistry B, Vol. 117, 2013, Pages 5271-5279,
Surface plasmon polaritons and optical transmission through a vortex lattice in a film of type-II superconductor,” Berman OL, Lozovik YE, Kolesnikov AA, Bogdanova MV, Coalson RD , JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS , Vol. 30, 2013, Pages 909-913 , http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSear...
Calcium Inhibits Paracellular Sodium Conductance through Claudin-2 by Competitive Binding,” Yu ASL, Cheng MH, Coalson RD , Journal of Biological Chemistry, Vol. 285, 2010, Pages 37060-37069 , http://www.jbc.org/content/285/47/37060.full.pdf
The Electrostatics of VDAC: Implications for Selectivity and Gating ,” Choudhary OP, Ujwal R, Kowallis W, Coalson R, Abramson J, Grabe M, JOURNAL OF MOLECULAR BIOLOGY , Vol. 396, 2010, Pages 580-592, http://www.sciencedirect.com/science/article/pii/S0022283609014764
Dynamic Linear Response Theory for Conformational Relaxation of Proteins,” Author(s): Essiz SG, Coalson RD , JOURNAL OF PHYSICAL CHEMISTRY B, Vol. 113, 2009, Pages 10859-10869, http://pubs.acs.org/doi/pdf/10.1021/jp900745u
Molecular Basis for Cation Selectivity in Claudin-2-based Paracellular Pores: Identification of an Electrostatic Interaction Site ,” Yu ASL, Cheng MH, Angelow S, Gunzel D, Kansawa SA, Schneeberger EE, Fromm M, Coalson RD, JOURNAL OF GENERAL PHYSIOLOGY, Vol. 133, 2009, Pages 111-127, http://jgp.rupress.org/content/133/1/111.full.pdf+html
In Silico Models for the Human alpha 4 beta 2 Nicotinic Acetylcholine Receptor,” Haddadian EJ, Cheng MHY, Coalson RD, Xu Y, Tang P, JOURNAL OF PHYSICAL CHEMISTRY B, Vol. 112, 2008, Pages 13981-13990, http://pubs.acs.org/doi/pdf/10.1021/jp804868s
Computational prediction of ion permeation characteristics in the glycine receptor modified by photo-sensitive compounds,” Cheng MH, Coalson RD, Cascio M, Kurnikova M, JOURNAL OF COMPUTER-AIDED MOLECULAR DESIGN, Vol. 22, 2008, Pages 563-570, http://www.springerlink.com/content/b8513551414t4052/fulltext.pdf
Partitioning of a polymer chain between a confining cavity and a gel ,” Tsonchev S, Coalson RD, Duncan A, PHYSICAL REVIEW E, Vol. 76, 2007, Pages 041804, Part 1, http://pre.aps.org/pdf/PRE/v76/i4/e041804