Evaluation of the Morse potential function coefficients for germanene by the first principles approach.

In this paper, first principles calculations are used to investigate atomic structure and mechanical properties of germanene nanosheet. By applying uniaxial and biaxial tensile strains as well as shear strain, the tensile and shear properties of the germanene nanosheet, including Young's and bulk moduli, Poisson's ratio, and shear moduli are computed. Furthermore, the parameters of the modified Morse potential function are calculated for Ge-Ge interaction in the germanene nanosheet. Also, the mechanical behavior of germanene nanosheet is studied under tensile loading at large strains extended to the plastic range. Based on the simulations, Young's modulus of the armchair and zigzag germanene nanosheet are computed as 52.8 and 49.9N/m, respectively. Besides, the values of Poisson's ratio of the armchair and zigzag germanene nanosheet are obtained as 0.35 and 0.29, respectively.