Photocrystallography, a rapidly developing area in dynamic structural science, allows photoinduced structural changes and transient species to be studied. X-ray techniques have undergone rapid development but neutron photocrystallography has lagged behind because the percentage photoconversion achievable is low due to limited light penetration into the large crystals needed for high quality neutron diffraction data. We propose that the spin crossover compound [Fe(abpt)2(NCS)2] is an ideal system to develop and validate an innovative experimental design to allow photoexcitation by laser irradiation of single crystals on SXD. The cooperative nature of the phototransformation in spin crossover compounds overcomes light penetration problems and allows 100% conversion to the photoproduct. Understanding these systems is crucial to the development of optical switching and memory devices.