The results from the FLARE experiments, together with the interpretation of the large-scale conformational rearrangement of molecules associated with overcoming potential-energy barriers at T gβ , fully explains our previous observation regarding the critical role of T gβ for the crystallisation process from a disordered solid . Additionally, these results are in agreement with previous studies using gamma-rays, where in that particular work the authors observed that upon irradiation their sample underwent significant ageing thought to be caused by structural rearrangement due to pushing molecules over their energy barriers. In samples of a quench-cooled melt of naproxen (C 14 H 14 O 3 ), which contained crystalline nucleation seeds due to an insufficient cooling rate, we found that upon heating the crystallisation rate increased dramatically at temperatures above T gβ and full crystallisation was observed at temperatures well below T gα . Whilst our simple method of quench-cooling molten APIs can reliably produce stable glasses in most cases, this is not the scenario for naproxen -even when quenching the melt to liquid nitrogen temperatures -given its extremely high propensity to crystallise and limited heat transfer in our experimental apparatus. The resulting solid is hence mostly disordered, but there exists significant near-range order between a large number of molecules. For a system like this, further nucleation and crystal growth requires only the subtle movement of neighbouring molecules and no significant translational or (hindered) rotational motions, and as the potential-energy barriers that govern the conformational rearrangement are exceeded (at T gβ ), the crystallisation process can commence much more readily. This idea also explains why we observe the formation of different polymorphs during the stimulated crystallisation process by FLARE compared to the crystallisation at high temperatures. The near-range order in the disordered solid will determine the crystal structure that can form during FLARE excitation, as only the weak potential-energy barriers that are linked to the large-scale conformational rearrangement of molecules are pumped by the terahertz beam, implying there is no significant enhancement of the translational or (hindered) rotational motions associated with the terahertz stimulation. It is therefore not surprising that the polymorph formed during such crystallisation is not necessarily that with the lowest energy crystal structure, but the only that which is structurally closest to the near-range structure in the disordered solid. There is empirical evidence that different polymorphs may result from crystallising from melt-quenced, spray-dried, lyophilised or cryo-milled amorphous solids . It is important to note that while the net-outcome of these experiments produces crystalline phases, there is no evidence for or against other possible outcomes due to the terahertz radiation, for example accelerated aging or rejuvenation of the amorphous solid itself. Future experiments will have to confirm whether this is predetermined by the existing near-range order, as suggested in the literature, and whether it is hence possible to selectively crystallise different polymorphic forms from such disordered solids, e.g. by terahertz stimulation.