First-principles calculations of the theoretical tensile strength of copper

Three ab initio calculations of the theoretical tensile strength of an ideal crystalline metal (f.c.c. Cu) are presented. The first two employ a full band-theoretic approach to compute the cohesive energy as a function of uniaxial lattice deformation. One of these is based on non-self-consistent KKR calculations using the muffin-tin approximation. The other uses the self-consistent augmented spherical wave (ASW) method. The third calculation is based on a new, non-empirical pair potential φ that can be expressed formally in terms of the cohesive energy E and can be evaluated if E is known as a function of the nearest-neighbour distance r₁. The theoretical tensile strengths obtained using these three approaches differ by about 40%, but all are consistent with available measurements.