Experimental and theoretical study of energy transfer in a chromophore triad: What makes modeling dynamics successful?
Abstract
Simulation of electronic dynamics in realistically large molecular systems is a demanding task that has not yet achieved the same level of quantitative prediction already realized for its static counterpart. This is particularly true for processes occurring beyond the Born–Oppenheimer regime. Non-adiabatic molecular dynamics (NAMD) simulations suffer from two convoluted sources of error: numerical algorithms for dynamics and electronic structure calculations. While the former has gained increasing attention, particularly addressing the validity of ad hoc methodologies, the effect of the latter remains relatively unexplored. Indeed, the required accuracy for electronic structure calculations to reach quantitative agreement with experiment in dynamics may be even more strict than that required for static simulations. Here, we address this issue by modeling the electronic energy transfer in a donor–acceptor–donor (D–A–D) molecular light harvesting system using fewest switches surface hopping NAMD simulations. In the studied system, time-resolved experimental measurements deliver complete information on spectra and energy transfer rates. Subsequent modeling shows that the calculated electronic transition energies are “sufficiently good” to reproduce experimental spectra but produce over an order of magnitude error in simulated dynamical rates. We further perform simulations using artificially shifted energy gaps to investigate the complex relationship between transition energies and modeled dynamics to understand factors affecting non-radiative relaxation and energy transfer rates.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 28, 2020
- Source ID
- 10.1063/5.0028126
Entities
People
- Alexander Mikhailovsky
- Cheng Zhou
- Dianelys Ondarse-alvarez
- Guillermo C. Bazan
- Parmeet Nijjar
- Sebastian Fernandez-Alberti
- Sergei Tretiak
- Tammie Nelson
- Victor M. Freixas
Organizations
- Agencia Nacional de Promoción Científica y Tecnológica
- Army Research Office
- Center for Integrated Nanotechnologies
- Los Alamos National Laboratory
- National Scientific and Technical Research Council
- National University of Quilmes
- United States Department of Energy
- University of California, Santa Barbara
- University of Southern California
- Yusuf Hamied Department of Chemistry