We evaluated the geometries of the curved and flat CoPcH4(CO) intermediates at varying charge to understand how CO binding affinity changes with potential. We investigated the N-Co-N angle, the Co-C distance, and the C-O distance (Fig. ). At all charges, the curved CoPcH4(CO) maintains a smaller N-Co-N angle than the flat analog, indicating more out-of-plane distortion (Fig. ). For both cases, the angle decreases as additional electrons are introduced (potential becomes more negative). This is likely because electrons are occupying the dyz orbital, and to minimize overlap with the in-plane p orbitals of the ligand, the Co distorts axially out of plane.