PES for the photodissociation of vinylacetylene (C₄H₄) on the ground electronic state. Energies (in kJ mol^–1), computed at the CCSD(T)-F12/cc-pVQZ-F12 level of theory, are given relative to ground-state vinylacetylene. Key intermediates and TSs connecting the H loss, H₂ loss, and C₂H₂/CCH₂ loss channels are shown. Note that the C₃H₃ + CH channel (650 kJ mol⁻¹) is not energetically accessible in photodissociation at 193 nm.