Fulvene has also been shown to be the multidimensional analogous of the popular Tully III analytical 1D model. Fulvene dynamics is characterized by ultrafast nonadiabatic processes involving S 1 ↔S 0 recurrences at an extended conical intersection seam. The molecule exhibits fast decay to the ground state (S 0 ) followed by periodic recurrences to the first excited state (S 1 ). In fulvene dynamics, the most relevant coordinates include the torsional angle around the C-CH 2 bond and the bond length between these carbon atoms. These coordinates are critical because they define the molecule's structural evolution as it moves toward the conical intersection at different regions of the crossing seam.