Computational Research On The High-pressure Stable Structure And Properties Of GaH₅ And H_xFS (x=4,6)

The realization of high temperature superconductivity has always been the dream and pursuit of scientists.For about a hundred years,the interest of exploring superconducting materials has continued unabated.The special properties of superconducting materials imply important microscopic mechanisms.More importantly,high temperature superconducting materials can bring a revolutionary impact on industry.Therefore,it is of great significance to search new superconducting materials.In this paper,we performed computational and theoretical studies on the structures and properties of the GaH₅ and H_xFS?x=4,6?hydrides at high pressures by using genetic algorithm?GA?method.The main researches are as follows:1.Prediction of stable structures and the properties of GaH₅ under high pressure.The results suggested that at the pressure range 150-400 GPa,the P2₁/m phase of GaH₅ is the most favorable phase and dynamically stable,but thermodynamically it is unstable.The GaH₅-P2₁/m phase exhibits metallic feature,its predicted T_c is about 35.63 K at 250GPa.2.Prediction of stable structures and properties of H_xFS?x=4,6?systems under high pressure.The stable structure of H₄FS at the pressure range 50-300GPa is the PMA2structure.In H₆FS,the most stable phase is H₆FS-P3M1 at 50 GPa.At 100 and 150 GPa,the stable one is the P1 structure.Above 150GPa,the stable phase is AMM2.The results show that the H₄FS-PMA2 structure,the P3M1,AMM2 and R-3m structures of H₆FS are metallic,but only the R-3m structure of H₆FS is dynamically stable.