The electronic, stability and mechanical properties of the kagome lattice CsTi₃Bi₅ under pressure: a first-principles study

The kagome lattices of the<i>A</i>Ti₃Bi₅family have recently garnered significant attention due to their superconducting and topological properties. Here, we conducted an in-depth analysis of the band structure of the prototypical titanium-based kagome lattice material, CsTi₃Bi₅, using Density Functional Theory. We revealed its topological properties and demonstrated that the Van Hove singularities can be effectively tuned to the Fermi level under 18 GPa. Our findings confirm the dynamic stability of the CsTi₃Bi₅system and further demonstrate that its elastic constants, which comply with Born's criteria, ensure mechanical stability. The Poisson's ratio and Pugh's ratio indicate good ductility, while the material exhibits relatively low hardness. Notably, the mechanical properties exhibit significant directional anisotropy under all pressure conditions. As a key material in kagome lattices, the research results on CsTi₃Bi₅provide theoretical insights for experimental studies and the preparation of similar materials.