Vibronic intensities in intraconfigurational spin-forbidden luminescence spectra of Mn(V) in apatite and spodiosite lattices provide a rigorous test for a time-dependent theoretical model. The intensities are induced by spin-orbit coupling between the state corresponding to the spin-forbidden transition and a nearby state corresponding to a spin-allowed transition. Short progressions are observed in totally symmetric Mn-O modes even though no changes in the orbital populations, bond properties. or force constants are expected. The vibronic intensities are calculated by using the numerical integration of the time-dependent Schrodinger equation and the time-dependent theory of electronic spectroscopy. The experimental emission and excitation spectra of Gudel and coauthors provide a rigorous test of the theory because the input parameters are precisely measured or constrained within a narrow range determined by the experimental uncertainty. The calculated intensities of vibronic bands in the emission spectra are in excellent agreement with the measured values. The spectra are interpreted in terms of the probability density of the eigenfunctions of the coupled systems. Trends and sensitivities of the vibronic intensities to changes in the input parameters such as coupling strength, energy separation of the states, and bond length changes between the ground and excited states are discussed.