Structure and photochemistry of a bio-inspired model for photocatalytic H₂O splitting: Improved calculations of the Sobolewski and Domcke's Chlorophyll-Imidazole-Benzoquinone model complex

Abstract

The photoelectron spectrum of a bio-inspired model supramolecule that consists of a truncated chlorophyll, imidazole, and benzoquninone is explored with the equation of motion coupled cluster method (EOM–CCSD). The motivation for this study is to highlight the capabilities of the massively parallel implementations of closed- and open-shell CC methods in ACES III and to augment recently published results with the approximate resolution of identity CC singles and doubles (RI‐CC2) method. Furthermore, we have also obtained the structure of the supramolecule at the second-order many body perturbation theory (MBPT(2)) level with two different basis sets and compared our structure with previous density functional theory (DFT) results.

Keywords:

• artificial photosynthesis
• bio-inspired models
• hydrogen fuel
• equation of motion coupled cluster method

Acknowledgements

Both Ajith Perera and Jorge A. Morales were graduate students at the University of Florida's Quantum Theory Project (QTP) in the early 1990s. Prof. Bartlett, to whom this special issue is dedicated, was a mentor to both. Ajith Perera is one of Rods’ PhD students and a long-time collaborator. We fondly remember graduate classes taught by Prof. Bartlett, which were our first foray into the beauty of the many-body theory, and it is with great pleasure that we dedicate this contribution in Rod's honour. Ajith Perera also acknowledges the support of the United States Air Force Office of Scientific Research (AFOSR) and the Army Research Lab (ARL) sponsored DURIP support through Dr. James Parker for a dedicated cluster to the University of Florida (UF) HPC (HiperGator). Dr. Charles Taylor, associate director of UF Research computing, is especially acknowledged for facilitating these large time-consuming calculations.

Additional information

Funding

Jorge A. Morales acknowledges support from the National Science Foundation grant [CHE-0645374 (CAREER)] and a grant from the donors of The American Chemical Society Petroleum Research.