Electronic and Thermophysical Properties of Gas Hydrates: Ab Initio Simulation Results

Abstract

Abstract: Results of ab initio molecular-dynamic investigation of the electronic and thermophysical properties of methane hydrate with cubic structure sI are represented. The simulation results for specific heat at constant volume and density are in good agreement with experimental data. The temperature dependences of the electronic properties of methane hydrate (including Fermi energy level and width and edges of the band gap) are determined based on analysis of the density of electronic states. For an empty hydrate framework (aqueous clathrate framework), the spectra of electron energy E(k) along the M–X, X–Γ, Γ–M, and Γ–R directions are calculated. It is established that the presence of CH4 molecules in the aqueous clathrate increases the hydrate Fermi energy from 2.4 to 3.0 eV.