First-Principles Studies of the Excited States and Optical Properties of Xanthene Derivative Chromophores

ORAL

Abstract

Elucidation of the energy transfer mechanism in natural photosynthetic systems remains an exciting challenge. In particular, biomimetic protein-pigment complexes provide a unique study space in which individual parameters are adjusted and the impact of those changes captured. Here, we compute the excited state properties of a group of xanthene-derivative chromophores to be employed in the construction of new biomimetic light harvesting frameworks. Excitation energies, transition dipoles, and natural transition orbitals for the low-lying singlet and triplet states of these experimentally-relevant chromophores are obtained from first-principles density functional theory. The performance of several exchange-correlation functionals, including an optimally-tuned range-separated hybrid, are evaluated and compared with many body perturbation theory and experiment. Finally, we will discuss the implication of our results for the bottom-up design of new chromophores.

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Authors

  • Samia Hamed

    UC Berkeley Department of Chemistry

  • Sahar Sharifzadeh

    Lawrence Berkeley National Laboratory, Molecular Foundry, LBNL, Molecular Foundry, Lawrence Berkeley National Laboratory, Molecular Foundry at LBNL, Lawrence Berkeley Natl Lab

  • Jeffery B. Neaton

    Department of Physics, UC-Berkeley; Molecular Foundry, LBNL, Molecular Foundry, LBNL, Department of Physics, UC Berkeley, Molecular Foundry, LBNL and Dept. Physics, UC Berkeley, Molecular Foundry, Lawrence Berkeley National Laboratory and Department of Physics, University of California, Berkeley, UC Berkeley, Dept of Physics; Materials Science Division, LBNL, Molecular Foundry, Lawrence Berkeley National Laboratory; Department of Physics, UC-Berkeley, The Molecular Foundry, LBNL; Dept. of Physics, University of California, Berkeley, Lawrence Berkeley National Laboratory, UC Berkeley Department of Physics, Lawrence Berkeley Natl Lab and Department of Physics, UC-Berkeley, Physics Department, UC Berkeley; Molecular Foundry, Lawrence Berkeley National Lab