Density Functional Theory Calculation of N–H2S Hydrate

This study establishes a high-symmetry water cage structure model (structure N) based on the density functional theory first-principles technique. Three high-symmetry H2S hydrates (N–H2S hydrate) are examined in terms of their geometric structures, electrical characteristics, and optical characteristics. The structure of three N–H2S hydrates is most stable when H2S is in the center of water cage with small hydrogen bonds, and the molecular orientation of H2S has little effect on the structure of hydrate. The energy band of H2S enters forbidden band, resulting in the band gap of N–H2S hydrate being much less than that of water cage. A formation energy of −0.128 eV is reached when H2S DOS shift to the higher energy zone and the water cage DOS shift more to the lower energy region. The three N–H2S hydrates also possess various reflectivity characteristic peaks in the energy range of 5–12.5 eV, which might be exploited for electromagnetic detection of N–H2S hydrates. The findings of this research may serve as a theoretical foundation for related experiments.