Relationship between molecule structure of HMX and nitrogen-14 nuclear quadrupole resonance frequency

The NQR frequency at resonance of solid substance is determined by the atomic nucleus and the electricity field gradient outside. For same atomic nucleus, the NQR frequencies are primarily determined by the electricity field gradient outside the atomic nucleus. The nuclear quadruple resonance frequency, the nuclear quadrupole coupling constant, and the electricity field gradient of nitrogen atom on the ring of HMX were calculated by Hartree-Fock equation at different levels. The relationship between molecule structure of HMX and nuclear quadrupole resonance frequency was described, and the calculated value was compared and analyzed with the experiment value. The study shows that the experimental value is properly accordance with the calculated value at the level of D95 and D95v1. This study provides a method for determining the NQR frequencies of substance with similar structures.