Data-driven search for high-temperature superconductors in ternary hydrides under pressure
Beibei Jiang, Xiaoshan Luo, Ying Sun, Xin Zhong, Jian Lv, Yu Xie, Yanming Ma, Hanyu Liu
Abstract
Recently, ternary clathrate hydrides have become promising candidates for high-temperature superconductor. However, it is a formidable challenge to effectively hunt high-temperature superconductivity among multinary hydrides due to the expensive computational cost associated with large unit cells and huge stoichiometric choices. Here, we present an efficiently data-driven strategy, including generated clathrate frameworks, the quick estimation of stability for each framework, and superconducting critical temperature (${T}_{\mathrm{c}}$) for each hydride structure, to accelerate the discovery of high-temperature superconducting hydrides. Our strategy was initialized with more than one million input structures via zeolite databases and our generated dataset. As a result, such a strategy hitherto uncovered 14 prototypical hydrogen frameworks for clathrate hydrides, which is 1.5 times greater than the number (9) of previously reported prototypes. Remarkably, 11 ternary clathrate structures were predicted to have ${T}_{\mathrm{c}}$'s above 250 K at 300 GPa. Further extensive global structure-searching simulations support that $\mathrm{L}{\mathrm{i}}_{2}\mathrm{Na}{\mathrm{H}}_{17}$ and $\mathrm{Th}{\mathrm{Y}}_{2}{\mathrm{H}}_{24}$ are thermodynamically stable at 220 and 150 GPa, respectively, with ${T}_{\mathrm{c}}$'s approaching room temperature of 297 and 303 K, which are promising for future synthesis. These results offer a platform to explore high-temperature superconductors via a great number of databases.