Further, introducing the strain, mechanical response (Table ) and elastic anisotropy are calculated (Table ). Surprisingly, 6% of compressive strain is mechanically unstable. This suggests that the material is not machineable and hard to operate for any applications at this strain. Compressing the monolayer at 2%, the Young's and shear moduli decrease, however, Poisson's ratio increases abruptly up to 0.149, which is indeed comparable to that of graphene , the strongest 2D material till now. This abrupt growth of Poisson'ratio continues up to 0.324 at 4% strain indicating the ductile behavior. This fact is also supported by the maximum value (215.99) of Y . In addition, the anisotropy indices (Table ) describe the elastic anisotropic behavior of the monolayer. The zero value of anisotropy indices refers to the isotropic elastic response. Any change from that reference value indicates the degree of anisotropy. With the compressive strain, the indices, A , A Ranganathan , Kube shift to higher values indicating the increment in anisotropy. This fact is visualized by the polar plots (Fig. ), in which the curves of Young and shear moduli, and Poisson's ratio gradually deform with the increase in compressive strain. The highest values of Young's modulus, Poisson's ratio, and shear modulus for the strain-free monolayer are located along the (100) (0 • ), (110) (45 • ), and (010) (90 • ), respectively, while minimum values are at (010) (90 • ), (010) (90 • ), and (110) (45 • ), respectively. This result is in good agreement with available literature . These maxima and minima fluctuate to different values with strain (Fig. ).