Metallization and superconductivity in potassium-doped methane

Abstract

Metallization of methane (CH 4 ) has always been an interesting issue. Here, we report a study on the structure, metallization and superconductivity in K-doped CH 4 under pressure, based on the particle swarm optimization, density functional theory, and density functional perturbation theory. Summarizing the thermodynamical and dynamical stabilities, the electronic band structures, and the electron–phonon interaction calculations, we predicted that K-doped CH 4 in [Formula: see text] space-group is a metal and a possible superconductor in the pressure range of [Formula: see text] GPa. The superconducting critical temperature is about 12.7 K at 80 GPa. It was found that the charge transfer from K to CH 4 drives the metallization and mainly contributes to the electron–phonon interaction. The result confirms that CH 4 can become a metal and superconductor under the electron doping and the relative low pressure.