Atomic-scale calculation of energies of Cu (001) twist boundaries

Unrelaxed energies for Cu (001) twist grain boundaries (GBs) are calculated using a Modified Analytical Embedded Atom Method (MAEAM). The results show that, except zero energy at 0 degrees (perfect crystal), a small cusp exists at a twist angle of 36.87 degrees corresponding to Σ = 5, which agrees with experimental results. For other misorientations, the GB energies keep almost constant even at a twist angle as small as 1.94 degrees. Homogeneous expansion and the expansion perpendicular to the GB plane result in obvious decrease of energy, especially the latter.