Description This dataset contains the results of nonadiabatic molecular dynamics (NAMD) simulations of the photocyclisation reaction of a furylfulgide with a tert-butyl group at position C3. The nuclear wavepacket is represented by a set of 50 trajectories, which are numbered from 0 to 49. Each trajectory is formatted as a standard XYZ file, and it can be viewed with molecular editing software such as Jmol, GDIS, or VMD. The atomic coordinates are given in units of angstrom. The frames are written every time step (at intervals of 0.5 fs). Each trajectory lasts 500 fs. Each frame in each trajectory has a comment line, which gives the time t (in units of fs), the energy of the S0 state, the energy of the S1 state, the energy of the current state, and the total energy (in units of hartree). Acknowledgement This research was supported by the NCN grant Miniatura no. 2022/06/X/ST4/00523, and by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 847413.