The research in our group is aimed at the elucidation of the fundamental molecular-level origins of chemical behavior in condensed phases. Under these circumstances, the intimate interactions between molecules lead to both a complexity and a richness of phenomena. We emphasize realistic atomistic descriptions of complex molecular systems, and we focus on the development and application of theoretical and computational approaches to structural and dynamic chemical processes. These approaches are founded in classical and quantum statistical mechanics, and in quantum chemistry, as well as in the numerical methods underlying computer simulation.
Current topics of emphasis fall in several areas of chemical physics, biophysical chemistry, and materials science. In each case, establishing close contact with experimental observables is an essential feature of the calculations that we pursue.
The chemistry problems that we are focused on include:
- Chemistry in supercritical solvents
- supercritical water as a reaction medium: role of solvent density heterogeneity on thermodynamics; reaction activation free energies; transport properties.
- supercritical CO2-water interfacial systems: (NSF Science and Technology Center for Environmentally Responsible Solvents and Processes) origins of novel surfactant behavior
- Environmental and intramolecular effects on electronic dynamics
- electronic excited state dynamics and relaxation in condensed phases. Intramolecular electron transfer in both small molecules and proteins; carrier dynamics in semiconducting polymers; mechanistic photochemistry, interpretation of ultrafast spectroscopy.
- Aqueous solvation effects on molecular conformation, intersolute interactions, and solute electronic structure, including biomacromolecular solvation.
- Mixed quantum-classical and semiclassical simulation approaches for condensed phase systems. Implementation of algorithms for treating nuclear quantum effects and electronic quantum decoherence.
Representative recent publications:
P. B. Balbuena, K.P. Johnston, P.J. Rossky, and J-K. Hyun, "Aqueous Ion Transport Properties and Water Reorientation Dynamics from Ambient to Supercritical Conditions", J. Phys. Chem., 102, 3806 (1998).
O. V. Prezhdo and P.J. Rossky, "Relationship between quantum decoherence times and solvation dynamics in condensed phase chemical systems", Phys. Rev. Letters, 81, 5294 (1998).
Y-K Cheng, W-S Sheu, P. J. Rossky, "Hydrophobic Hydration of Amphipathic Peptides", Biophys. J. 76, 1734 (1999).
P. Minary, L. Turi, P. J. Rossky, "Non-adiabatic Molecular Dynamics Simulation of Photoexcitation Experiments for the Solvated Electron in Methanol", J. Chem Phys. 110, 10953 (1999).
J. Lobaugh, P. J. Rossky, "Solvent and Intramolecular Effects on the Absorption Spectrum of Betaine-30", J. Phys. Chem. 104, 899 (2000).
J. Lobaugh, P. J. Rossky, "Computer Simulation of the Excited State Dynamics of Betaine-30 in Acetonitrile", J. Phys. Chem. 103, 9432 (1999).
D. M. Lockwood, P. J. Rossky, R. M. Levy, "Functional Group Contributions to Partial Molar Compressibilities of Alcohols in Water," J. Phys. Chem. B 104, 4210 (2000).
D. Hu, J. Yu, K. Wong, B. Bagchi, P. J. Rossky, P. F. Barbara, "Collapse of Stiff Conjugated Polymers with Chemical Defects into Ordered, Cylindrical Conformations," Nature 405, 1030 (2000).
C. Carey, Y-K Cheng, P.J. Rossky, "Hydration Structure of the a-Chymotrypsin Substrate Binding Pocket: the Impact of Constrained Geometry," Chemical Physics 258, 415 (2000).