Li Huan, Gao Tao, Ma Shiyin, Ye Xiaoqiu
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
Science and Technology on Surface Physics and Chemistry Laboratory, Jiangyou, 621908, China.
Phys Chem Chem Phys. 2022 Apr 6;24(14):8432-8438. doi: 10.1039/d2cp00059h.
The structures of LiYH ( = 5-10) compounds in the pressure range of 0-300 GPa have been extensively explored using the CALYPSO structure prediction method based on the particle swarm optimization algorithm and first-principles calculation. Four stable structures (2/ LiYH, 2/ LiYH, 1̄ LiYH, 3̄ LiYH) and three metastable phases ( LiYH, 1̄ LiYH, LiYH) were predicted. They all exhibit metallic and superconducting behavior in their respective stable pressure ranges, and the predicted superconducting transition temperature is within 22-109 K when the pressure is greater than 100 GPa. It was found that after doping Li into YH ( = 6, 9, 10), the H units in the system increased, the electron-phonon coupling interaction weakened, and decreased when the structural characteristics, electronic density of states distribution, and superconductivity of LiYH and YH ( = 6, 8, 9, 10) were compared. Systems that have a high density of H_s states and a low number of Y_d states at the Fermi level have stronger electron-phonon coupling (EPC) interactions and higher .
利用基于粒子群优化算法和第一性原理计算的CALYPSO结构预测方法，对LiYH（= 5 - 10）化合物在0 - 300 GPa压力范围内的结构进行了广泛探索。预测出了四种稳定结构（2/LiYH、2/LiYH、1̄LiYH、3̄LiYH）和三种亚稳相（LiYH、1̄LiYH、LiYH）。它们在各自的稳定压力范围内均表现出金属性和超导行为，且当压力大于100 GPa时，预测的超导转变温度在22 - 109 K范围内。研究发现，在YH（= 6、9、10）中掺杂Li后，系统中的H单元增加，电子 - 声子耦合相互作用减弱，并且在比较LiYH和YH（= 6、8、9、10）的结构特征、态密度分布和超导性时，超导转变温度降低。在费米能级处具有高密度H_s态和低数量Y_d态的系统具有更强的电子 - 声子耦合（EPC）相互作用和更高的超导转变温度。
