Cyclo-1,3,5-trinitramine-2,4,6-trimethylene (RDX) is a principal energetic component in many high performance military explosives. [R. Meyer,Explosives, 2nd ed. (Chemie, Weinheim, 1981), p. 74.EncyclopediaofExplosivesandRelatedItems, PATR 2700, edited by S. M. Kaye and H. L. Herman (Picatinny Arsenal, Dover, NJ, 1966), p. C611]. Optical quality single crystal RDX has been obtained and examined by x-ray photoelectron spectroscopy prior to the input of shock damage as a control experiment. The effect of localized crystalline disruption, as generated by a hardness impression, on the shock energy threshold for the creation of chemical decomposition is to be assessed. The data reported here are from the undamaged material.