14N quadrupole resonance and 1H T1 dispersion in the explosive RDX

► Temperature variation of 14N NQR T1, T2, T2e and of 1H NMR T1 dispersion for RDX. ► Explained in terms of hindered rotation of the NO2 groups about the N-N bond. ► With an activation energy of ≈90 kJ mol−1 similar to that in many nitro compounds. ► Temperature dependence of the 14N NQR line-widths. ► Due to a distribution of N-NO2 torsional frequencies at defects or impurity sites.