First‐Principles Study of the Structural, Elastic, and Mechanical Properties of Cubic CsF Under Hydrostatic Compression

ABSTRACT

We investigate the structural and mechanical properties of cubic CsF under hydrostatic pressure using first‐principles calculations. The computed equilibrium lattice constant and elastic constants are in good agreement with available experimental data, validating the computational approach. Under compression, the elastic constants increase monotonically and satisfy the Born–Huang stability criteria, indicating enhanced mechanical stiffness. The calculated bulk, shear, and Young's moduli, together with Pugh's ratio, identify cubic CsF as a ductile material with moderate incompressibility, while a small elastic anisotropy is observed and increases with pressure. The hardness is found to increase significantly under compression, reflecting improved resistance to plastic deformation. These results establish cubic CsF as mechanically stable over a wide pressure range and suitable for applications requiring robustness under stress.