Finally, the 'electronic properties' category has a greater impact on the shear modulus than the bulk modulus. The shear modulus is linked to a material's stiffness and its ability to resist deformation under shear stress. The electronic properties of a material can affect its stiffness by modifying the bonding interactions between atoms or the density of states near the Fermi level . For instance, in certain metals, the existence of unfilled electronic states can boost the strength of the metallic bond, thereby increasing the material's resistance to deformation. Similarly, the valence electrons in a material can affect its shear modulus by changing the bonding interactions between atoms or the density of states near the Fermi level.