A low energy electron beam (15 KeV) induced dimensional instability is observed in 2,4,6-Trinitrotoluene single crystals. The instability is characterised by shrinkage and relaxation whose Arrhenius plots resulted in the activation energies of the order of bond energies indicating molecular transformations which are confirmed by Laser Raman Spectroscopy recorded in the NO2symmetric stretching frequency range. The negative charge developed on the surface of the crystal by electron bombardment induces interaction with the electron deficient TNT molecules which rearrange among themselves causing crystal contraction and spiral loops on the surface.