AbstractThe DREIDING force field was chosen to predict the molecular packings for the three polynitroadamantanes (PNAs) with 8–10 ‐NO2 among the 7 most possible space groups (P21/c, P‐1, P212121, P21, Pbca, C2/c and Pna21) using molecular mechanics (MM) method, respectively. Then, ab inito periodic calculations were performed on the three predicted crystals using the DFT‐GGA‐RPBE method. Density of states (DOS) calculations showed that C–N bond was the trigger bond of PNA during thermolysis; band gaps (ΔE) were used to predict their relative sensitivity. All of these are consistent well with those drawn from bond dissociation energy calculation on gas molecules. Besides, our calculations present that variations of PNAs molecular structures from gas to crystal become smaller with the number of ‐NO2 groups increasing.