Location: Aud VI (Chemistry), Room 1510-213

Title: "Electronic resonances in photoactive biomolecules"

Speaker: Dr. Ksenia Bravaya,

Department of Chemistry, Boston University

Web: http://people.bu.edu/kbravgrp/index.html

 
Abstract:
Photoinduced electron transfer lies in the basis of such processes as
photosynthesis, DNA damage repair by photolyases, and many others.
Bottom-up approach to understanding these complex processes implies,
first, understanding the photoinduced processes in the isolated
biochromophores. Commonly, excited electronic states of the
biochromophores exhibit metastable character with respect to electron
detachment (autoionizing resonances), and, thus, possess finite
lifetime. The information on the lifetime of the resonance is,
therefore, of primary importance for disentangling complex
photoinduced dynamics in the systems.

I will discuss the recent progress in the development of electronic
structure methods capable of description of resonance electronic
states.  The methods are based on the equation-of-motion
coupled-cluster model with single and double substitutions (EOM-CCSD)
combined with complex-absorbing potential (CAP) technique [1]. The
performance of the method for description of autoionizing states in
medium-sized molecules of biological relevance will be demonstrated
[2].

[1] D. Zuev, T.C. Jagau, K.B. Bravaya, E. Epifanovsky, Y. Shao, E.
Sundstrom, M. Head-Gordon, and A.I. Krylov, J. Chem. Phys. 141 (2014)
024102.
[2] A.A. Kunitsa and K.B. Bravaya J. Phys. Chem. Lett. 6 (2015) 1053–1058.