Roles of coherence, delocalization, and intrachromophoric structure in FMO energy transfer

Determine the roles of electronic coherence, exciton delocalization, and intrachromophoric electronic structure in governing energy-transfer dynamics and trapping efficiency within the Fenna–Matthews–Olson (FMO) photosynthetic complex.

Background

The Fenna–Matthews–Olson (FMO) complex is a standard model system for studying photosynthetic energy transfer due to its well-characterized structure and energetics. Despite extensive work, the mechanistic contributions of electronic coherence, exciton delocalization, and intrachromophoric electronic structure to energy transfer and trapping efficiency have not been definitively established.

This paper introduces an extended excitonic network model that incorporates intrachromophoric electronic mixing while preserving pigment–pigment coupling topology, aiming to probe how these internal degrees of freedom affect coherence, delocalization, and transport. The authors emphasize that, even with such modeling advances, clarifying the precise roles of these factors remains an open question.