Density Functional Theory Calculation of Structure and Electronic Properties in N-Carbon Dioxide Hydrate

Abstract

We chose the first-principles method of density functional theory to study new carbon dioxide hydrate structures, obtain structure, electronic and optical properties. The results show that the side length and hydrogen bond length of the N-carbon dioxide hydrate water cage will not change significantly with CO2, the structure H binding energy is −0.247 eV that is the most stable. The binding energy and volume changes indicate that CO2 molecule has a very weak effect on the water cage which belongs to the van der Waals force, CO2 molecule can stabilize the water cage structure. The addition of CO2 molecule causes the bottom of the configuration’s conduction band to shift down and the band gap value decreases. The density of states of CO2 molecule in the hydrate shifted to the left while the density of states of the water cages did not change much, the s state electrons change slightly in the energy region of 5–15 eV. The N-carbon dioxide hydrate’s ability to store electromagnetic fields in the low frequency range is enhanced, it is weakened in the high frequency range. The microwave loss in the 2.5–25 eV frequency band increases and the reflectivity peaks at 9.06 eV.