Novel Topological Motifs and Superconductivity in Li-Cs System
Hongmei Huang, Qiang Zhu, Vladislav A. Blatov, Artem R. Oganov, Xiaoting Wei, Peng Jiang, Yanling Li
Abstract
In this work, we determined the phase diagram and electronic properties of the Li-Cs system by using an evolutionary crystal structure prediction algorithm coupled with first-principles calculations. We found that Li-rich compounds are more easily formed in a wide range of pressures, while the only predicted Cs-rich compound LiCs 3 is thermodynamically stable at pressures above 359 GPa. A topological analysis of crystal structures concludes that both Li 6 Cs and Li 14 Cs have a unique topology that has not been reported in existing intermetallics. Of particular interest is the fact that four Li-rich compounds (Li 14 Cs, Li 8 Cs, Li 7 Cs, and Li 6 Cs) are found to be superconductors with a high critical temperature (∼54 K for Li 8 Cs at 380 GPa), due to their peculiar structural topologies and notable charge transfer from Li to Cs atoms. Our results not only extend an in-depth understanding of the high-pressure behavior of intermetallic compounds but also provide a new route to design new superconductors.