The comparative study of structural, electronic, and optical properties of hydrogen peroxide and its dihydrate under pressures: first-principle calculations

Hydrogen peroxide (H₂O₂) is used as a fuel and propellant in fuel cells and rockets due to its prominent oxidizing and combustion properties. In addition, hydrogen peroxide, as the energetic material with the simplest molecular structure, exhibits general detonation performance under external stimulation. Based on the first-principle method, we calculated the two crystal structure, electronic properties related to sensitivity closely, optical properties of pure hydrogen peroxide, and 48wt.% hydrogen peroxide (H₆O₄) under pressure. We found that the band gaps of H₂O₂ and H₆O₄ become larger under pressure and the former is larger than the latter; neither has the tendency of metallization phase change. The added peak II of TDOS from H₆O₄ compared with H₂O₂ come from molecular H₂O in crystal structure. The pressure-induced peak (peak 2 and peak II of TDOS from H₂O₂ and H₆O₄) splitting is caused by changes (stronger) in the intermolecular hydrogen bond environment in the crystal under pressure. The specific macroscopic optical properties have the characteristics of overall blue-shift under pressure, which is due to the blueshift of the conduction band and the increase of the band gap. We hope to provide some reference and guidance for deeper future research.