ure ). For butene, we interpolated geometries between the optimized cis-(θ = 180 • ) and trans-isomer ). Notably, in the vicinity of the typical S 1 /S 0 conical intersection for photoinduced isomerization, particularly around θ of 90 • , we sampled the path in smaller increments of 9 • instead of 18 • steps. Since ethene and propene lack cis and trans-isomers and due to symmetry reasons, we generated five additional geometries for these molecules with HC=CH dihedral angles of 18, 36, 54, 72, and 90 • , in addition to their equilibrium structures (θ = 0 • ). For geometry interpolation, the Nudged Elastic Band (NEB) approach as implemented in orca was employed using PBE0/def2-TZVP 11-13 level of theory.