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Faculty

Raymond Sadeghi, Ph.D.

Research Assistant Professor

Office: FLN 3.01.28
Phone: (210) 458-5747
Email: raymond.sadeghi@utsa.edu

Areas of Specialization

» Simulation of chemical reactions
» Simulation of photodissociation dynamics
» Theoretical chemistry


Research Interests

The application of theoretical models to important problems in chemistry is the focus of my research program. Topics currently under study can be grouped into two broad categories: 1) small molecule chemical physics, and 2) collisional energy transfer between gas phase molecules. The typical Ph.D. thesis produced by students in my group will contain a mix of computer simulations, analytical modeling, and an analysis of experimental data. For all the projects presently underway, there is a strong emphasis on interfacing with state-of-the-art experimental work.

The process of translational, rotational, and vibrational energy interconversion during collisions remains a topic of great interest and not yet fully understood. Recent experiments on collional energy transfer between highly vibrationally excited molecules of azulene (C10H8) and krypton atoms have revealed results which are not replicated by the current available theoretical models that utilize a mixture of quantum mechanical calculations along with classical trajectory methods without a global potential energy surface. We shall develop a semiclassical wave packet method to approach the quantum dynamics and obtain the differential cross section.

In small molecule chemical physics, areas of particular interest include: theory of chemical reactions in the gas phase, and dynamics of molecular collisions. In the last few years, my strongest emphasis has been on transition state spectroscopy. This is due in no small part to the influx of new high-quality experimental results requiring interpretation. Recently, I have utilized the theory of END (Electron Nuclear Dynamics) to study chemical reactions at high energies. The simulations are motivated by recent experimental findings. END is a formulation of the complete dynamics of electrons and nuclei of a molecular system that eliminates the necessity of constructing potential energy surfaces which are computationally costly, and in most cases, implausible.

 

Publications

Buddhadev Maiti, Patrick M. McLaurin, Raymond Sadeghi, S. Ajith Perera, Jorge A. Morales "Dynamics for the dynamic Frank Harris: Exploring H+ + CF4 at Elab = 20 and 30 eV" Int. Jour. Quantum Chem. 2009, 109: 3026–3035.
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Buddhadev Maiti, Raymond Sadeghi, Anthony Austin, Jorge A. Morales "Coherent-states dynamics of the H+ + HF reaction at Elab = 30 eV: A complete electron nuclear dynamics investigation" Chem. Phys. 2007, 340, 105.

Raymond R. Sadeghi and Hai-Ping Cheng "The dynamics of proton transfer in a water chain" J. Chem. Phys. 1999, 111, 2086.
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Rex T. Skodje, R. Sadeghi, Jeffrey L. Krause "Control of transition state spectra: a variational algorithm" Chemical Physics 1999, 240, 129-139.
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Raymond R. Sadeghi, Steven R. Gwaltney, Jeffrey L. Krause, Rex T. Skodje and Peter M. Weber "Structure and dynamics of the S3 state of CS2" J. Chem. Phys. 1997, 107, 6570.
» abstract

Rex T. Skodje, R. Sadeghi and Jeffrey L. Krause "Quantum dynamics at the transition state Spectralquantization and spectral control theory applied to the FH2 photodetachment process" J. Chem. Soc., Faraday Trans. 1997, 93, 765-772.
» abstract

R. Sadeghi and Rex T. Skodje "Control of transition state spectra: Enhancement of diffuse structure in the photodissociation spectrum of CO2" J. Chem. Phys. 1996, 105, 7504.
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Additional Accomplishments
  • Developed a faster Data Base using Oracle 8i (Dell Inc., Austin, TX )
  • Kinetic modeling of combustion of methane using Runge-Kutta and techniques in the field of non-linear dynamics. The experiments were done at Argonne National Laboratories where we obtained the necessary rate-constants required for the simulations.