First-principle study and Hirshfeld surface analysis on the effect of H2O, NH3 and H2S on structural, electronic, elastic, optical and thermodynamic properties of a novel high-energy crystal 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide

2,4,6-Triamino-5-nitropyrimidine-1,3-dioxide (ICM-102) is a new high-energy crystal which has outstanding combination of performance, effects of three common small molecules H2O, NH3 and H2S on its molecular, crystal and electronic structures, and elastic, optical and thermodynamic properties of the compound were studied by the first-principle calculation and Hirshfeld surface analysis in this work. The results showed that H2O, NH3 and H2S do have significant effects on the structure and property of ICM-102, and different molecules made various influence on all kinds of properties. The low-sensitivity feature of ICM-102 was confirmed, and H2O molecule was found to further increase the stability of ICM-102 crystal obviously by enriching different kinds of close contacts. While the stabilization effect of NH3 and H2S on the ICM-102 was weaker than that of H2O and H2O also improved the density, stiffness, fracture strength and ductility, absorption to purple, blue, green and yellow lights, and thermodynamics parameters of ICM-102, but it decreased the band gap, anisotropy, plasticity, absorption to near ultraviolet and orange, red and infrared lights, and dielectric constant. However, different to H2O, NH3 and H2S reduced stiffness, fracture strength and ductility but increased the band gap of ICM-102. Besides, H2S was found to completely eliminate the region where light cannot be transmitted in the solid crystal ICM-102. This study may be helpful for using small molecules to stabilize the structure and adjust the property of energetic materials.