Structural and mechanical properties of ThB4 under tensile and shear strains

The structural and mechanical properties of ThB 4 under tensile and shear strains are analyzed using through first-principles calculations utilizing density functional theory. Using the Voigt–Reuss–Hill (VRH) approximation, the bulk modulus, shear modulus, and Young’s modulus are calculated as 201.58, 182.66 and 420.86 GPa, respectively. ThB 4 exhibits its lowest tensile strength of 34.0 GPa along the [110] direction. Under shear strain, fracture occurs along the [001] direction within the (110) plane, with a maximum stress of 27.0[Formula: see text]GPa. The remarkable mechanical properties of ThB 4 primarily arise from the B6 octahedra. The variations in B bond lengths under tensile and shear strains are systematically analyzed. The breaking of B bonds within the B 6 octahedra is responsible for the fracture of ThB 4 .