Methane (CH₄), the simplest hydrocarbons, will be a potential high-temperature superconductor if it can be transformed into metal.

However, pure CH₄ is a wide-gap semiconductor at ambient pressure. Even the pressure is set up to at least 520 GPa from experimental and theoretical studies, the band gap will not narrow. This indicates that the conversion of pure CH₄ to metal by simple pressurization still faces challenges. 

Dr. ZHONG Guohua and LI Wenjie at the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences systematically studied the structures and physical properties of methane doped by beryllium at low pressure and addressed these problems by the first-principles theory. 

The results showed that based on the particle swarm optimization, density functional theory and density functional perturbation theory, CH₄ can be transformed into metal and become a superconductor by doping Be.

The researchers predicted the crystal structure, electronic and dynamical properties, and electron-phonon interaction of BeCH₄ under certain pressure. Within the pressure range of 0-100 GPa, there were three thermodynamically stable phases in BeCH₄ : P-1 phase (0 ≤ P ≤ 25.6 GPa), a-P21 phase (25.6 < P < 50 GPa), and c-P1 phase (50 ≤ P ≤ 100 GPa).

The P-1 phase can realize metallization under normal pressure, and a superconducting transition occurs, indicating that CH₄ can be regarded as a new type of superconductor under electron doping and relatively low pressure.

The metastable phase of a-P1 of BeCH₄ has a superconducting critical temperature of 30 K at 80 GPa. Although the critical temperature of BeCH₄ is less than room-temperature, this work provides a guiding road to the high temperature and low pressure superconductivity. 

The study entitled "Metallization and superconductivity in methane doped by beryllium at low pressure" was published in International Journal of Modern Physics C.