(GQR29) Selective Activation of Latent Hexagonal Geometry in Crystalline Catalytic Systems Geometry-Driven Bifurcation and Pathway Selection Across the OEC Reaction Cycle.

Crystallographic symmetry provides a precise description of catalytic structure,yet how such symmetry constrains catalytic dynamics across reaction states remainsunclear. Using a crystallographic series of the photosystem II oxygen-evolving com-plex (8F4G–J), we analyse geometric structure across reciprocal space, autocorrelationspace, and shell-resolved real-space reconstructions. We find that geometrically allowedhexagonal support is not uniformly realised, but is selectively activated and progres-sively pruned in a state-dependent manner. A marked geometric bifurcation appearsnear state I, followed by directional restriction and valving in state J. Notably, func-tional order emerges first in correlation geometry rather than in spectral magnitudealone. Together, these results show that crystallographic symmetry acts as a dynamicconstraint on non-equilibrium catalytic pathways, providing a direct operational linkbetween crystal structure and catalytic function without invoking additional biologicalassumptions.