Title: Non-adiabatic Molecular Dynamics with DSCF Excited States (DSCF-NA-MD)

Speaker: Dr. Ekadashi Pradhan, SUNY Buffalo University

Abstract: Accurate modeling of nonadiabatic transitions and electron-phonon interactions in excited states of extended systems is essential for understanding charge and energy transfer in photovoltaic and photocatalytic materials. The demanding computational costs of post-Hartree-Fock or beyond-DFT methods have prompted researchers to create a number of approximate techniques for studying excited state dynamics in condensed matter systems. Recently, we developed a novel ∆SCF-NA-MD methodology that aims to capture electron-hole interactions and electron-phonon back-reaction important in photoinduced reactive dynamics. The excited states dynamics is described using delta self-consistent field (∆SCF) technique within the density functional formalism, fractional occupation numbers, and trajectory surface hopping. The new technique is implemented in the open-source Libra-X package freely available on internet [https://github.com/Quantum-Dynamics-Hub/Libra-X]. The formulation aims to be applicable to condensed-matter systems, but at this point validated by demonstrating its utility for modelling photoinduced nuclear and electronic dynamics in well-characterized molecules, for which the reference values of excited state energies, lifetimes, reorganization energies, or photoisomerization quantum yields are available.

In this presentation, I will elaborate conceptual aspects of the developed scheme and its implementation within the novel Libra-X package. Analysis of excited state dynamics in a number of organic molecules will be presented. Future applications of the current methodology for studying photoinduced dynamics in various materials, including condensed matter systems where photoinduced nuclear dynamics may play an important role will be discussed.

References

[1] A. V. Akimov, J. Comput. Chem., 2016, 37, 1626.

[2] E. Pradhan, K. Sato, and A. V. Akimov, J. Phys.: Condens. Matter, 2018, 30, 484002.

[3] K. Sato, E. Pradhan, and A. V. Akimov, Phys. Chem. Chem. Phys., 2018, 20, 25275.