Abstract：
Time-dependent density functional theory molecular dynamics (TDDFT-MD) [1] is the usual workhorse for studying excited-state (ES) dynamics, since it is computationally inexpensive. However, TDDFT-MD inevitably relies on adiabatic local density approximation (ALDA) [2], which is valid only for the initial state being the ground state and not for any initially excited state such as in photochemical reactions. Therefore, the results obtained with TDDFT-MD based on ALDA may be unreliable. The extended quasiparticle theory (EQPT) [3] has been shown to completely solve this problem. It guarantees the applicability of the GW approximation to any excited eigenstate as the initial reference state, contrary to conventional wisdom in the GW community. We have recently developed for the first time, a non-adiabatic dynamics methodology based on EQPT known as time-dependent GW molecular dynamics (TDGW-MD) to overcome the problem of ALDA for ES dynamics [4]. TDGW-MD exactly satisfies extended Koopmans’ theorem [5] and scales as ~O(NB3-4), NB – number of basis functions, which is distinctly advantageous to performing dynamics using configuration interaction. In the poster, I will show the mechanisms of important photochemical reactions using TDGW-MD, such as (a) the photolysis of methane [4, 6] as well as (b) the ring-opening mechanism in oxirane, as a way to demonstrate how TDGW-MD can be a major step towards traversing the excited-state dynamical landscape accurately.

References:
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[1] M. Petersilka, U. J. Gossmann, and E. K. U. Gross, Phys. Rev. Lett. 76, 1212 (1996).
[2] K. Ohno, S. Ono, and T. Isobe, J. Chem. Phys. 146, 084108 (2017).
[3] A. Manjanath et al., J. Chem. Phys. 160, 184102 (2024).
[4] D. W. Smith and O. W. Day, J. Chem. Phys. 62, 113 (1975).
[5] A. Manjanath et al., Nanomaterials 14, 1775 (2024).