Electronic and mechanical properties of SiNWs were studied based on First principle method via density functional theory. Effect of orientations on mechanical properties of silicon nanowire were identified. The elastic properties of {110}, {100}, {011} and {111} orientations were calculated. Due to atomic interaction in wires, various mechanical properties of wire changes were noted. The results show for strain 0.1164×10-5, 0.12×10-5 and 0.115×10-5 with modulus of 149.6GPa, 75.5GPa and 85.1GPa respectively.
