Alexey T. Zayak
My research is focused on atomistic simulations within density functional theory (DFT). I make use of advanced electronic structure software like VASP, PWSCF, SIESTA and PARSEC for computing crystalline or molecular properties with the goal of understanding basic mechanisms in materials chemistry. Modern computational theory is remarkably versatile: in addition to the widely applicable DFT that provides accurate chemical properties in most cases, there are more advanced methods that extend boundaries of DFT for describing more complex phenomena like, for example, van der Waals interactions or electronic excitations.
One of the most important aspects of my research is the ability to directly compare theory with experimental data. Raman spectroscopy, for example, utilizes interactions of light with atomic vibrations, providing unique fingerprints of any chemical species. Theory provides insight into electronic properties underlying this technique. Using first-principles calculations, we can analyse spectral information to the point of probing not only a chemical species itself, but also its immediate chemical environment. The ability to understand nano-scale spectroscopy opens remarkable prospects for new discoveries.
A. T. Zayak, H. Choo, Y. S. Hu, D. J. Gargas, S .Cabrini, J. Bokor, P. J. Schuck, and J. B. Neaton "Harnessing Chemical Raman Enhancement for Understanding Organic Adsorbate Binding on Metal Surfaces", J. Phys. Chem. Lett, 3, 1357-1362 (2012). Link
A. T. Zayak , Y. S. Hu, H. Choo, J. Bokor, S. Cabrini, P. J. Schuck, J. B. Neaton, "Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces", Phys. Rev. Lett. 106, 083003 (2011).
K. H. Khoo, A. T. Zayak, H. Kwak, and J. R. Chelikowsky, "First-principles study of confinement effects on the Raman spectra of Si nanocrystals", Phys. Rev. Lett. 105, 115504 (2010).
T.-L. Chan, A. T. Zayak, G. M. Dalpian, and J. R. Chelikowsky, "Role of Confinement on Diffusion Barriers in Semiconductor Nanocrystals", Phys. Rev. Lett. 102, 025901 (2009).
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