B.S. ('94), National and Kapodistrian University of Athens, Greece
RESEARCH GROUP http://astro.temple.edu/~smatsika/
Computational / Photonics / Physical
Most chemical processes follow the Born-Oppenheimer (adiabatic) approximation, in which the nuclei move on a single electronic potential energy surface (PES). However there are important processes where this approximation breaks down. These nonadiabatic events play an important role in essential processes in nature such as photosynthesis, vision, charge transfer and photochemistry. Nonadiabatic processes are facilitated by the close proximity of two PESs and the efficiency increases in the extreme case when two PESs become degenerate forming conical intersections. Theoretical developments have enabled the efficient study of conical intersections in small systems. The focus of our group is to extend these studies to more complicated systems, particularly of biological interest, in an effort to understand the underlying mechanisms of photoinitiated nonadiabatic processes and their potential implications.
Nonadiabatic processes are closely related to the processes involved in laser control of chemical reactions. In collaboration with experimentalists we aim at understanding the underlying mechanisms involved in laser control of basic chemical reactions, such as fragmentation and isomerization. Theory is used to interpret and guide the control.
Projects that we are working on involve:
M. Kotur, CY. Zhou, S. Matsika, S. Patchkovskii, M. Spanner, TC. Weinacht, "Neutral-Ionic State Correlations in Strong-Field Molecular Ionization." Physical Review letters. 109(20), 203007, (2012).
CY. Zhou, S. Matsika, M. Kotur, TC. Weinacht, "Fragmentation Pathways in the Uracil Radical Cation." Journal of Physical Chemistry A. 116(37), 9217-9227, (2012).
JP. Villabona-Monsalve, R. Noria, S. Matsika, J. Peon, "On the Accessibility to Conical Intersections in Purines: Hypoxanthine and its Singly Protonated and Deprotonated Forms." Journal of the American Chemical Society. 134(18), 7820-7829, (2012).
CH. Tseng, P. Sandor, M. Kotur, TC. Weinacht, S. Matsika, "Two-Dimensional Fourier Transform Spectroscopy of Adenine and Uracil Using Shaped Ultrafast Laser Pulses in the Deep UV." Journal of Physical Chemistry A. 116(11), 2654-2661, (2012).
P. Krause, S. Matsika, "Nuclear dynamics for a three-state Jahn-Teller model system." Journal of Chemical Physics. 136(3), 034110, (2012).
M. Kotur, TC. Weinacht, C. Zhou, S. Matsika, "Distinguishing between relaxation pathways by combining dissociative ionization pump probe spectroscopy and ab initio calculations: A case study of cytosine." Journal Of Chemical Physics. 134(18), 184309, (2011).
KA. Kistler, S. Matsika, "Photophysical pathways of cytosine in aqueous solution". Physical Chemistry Chemical Physics. 12(19), 5024-5031, (2010).
G. Kodali, KA. Kistler, M. Narayanan, S. Matsika, "Change in Electronic Structure upon Excitation of 8-Vinyladenosine: An Experimental and Theoretical Study". Journal of Physical Chemistry A. 114(1), 256-267, (2010).
M. Kotur, T. Weinacht, BJ. Pearson, S. Matsika, "Closed-loop learning control of osomerization using shaped ultrafast laser pulses in the deep ultraviolet". Journal of Chemical Physics. 130(13), 134311, (2009).
S. Matsika, "Two- and three-state conical intersections in the uracil cation". Chemical Physics. 349, 356-362, (2008).
KA. Kistler, S. Matsika, "Three-state conical intersections in cytosine and pyrimidinone bases". Journal of Chemical Physics. 128(21), 215102, (2008).
A. Yoshikawa, S. Matsika, "Excited electronic states and photophysics of uracil-water complexes". Chemical Physics. 347(1-3), 393-404, (2008).
C. Trallero, BJ. Pearson, T. Weinacht, S. Matsika, "Interpreting ultrafast molecular fragmentation dynamics with ab initio electronic structure calculations". Journal of Chemical Physics. 128(12), 124107, (2008).