Published online by Cambridge University Press: 26 February 2011
A parametrized tight-binding (TB) method based on the TB-UMTO approach in the atomic sphere approximation (ASA) [26] has been developed. The Hamiltonian is written in terms of the canonical structure matrix and potential parameters. The former is for a given configuration of atoms evaluated using a Dyson-type equation and the latter are those found self-consistently for the ideal lattice. A warping correction has been added to the scheme to be able to account for the effects of local straining which can not be included in the ASA. This is essential for applications in defect studies. Using this method the structure and energy of the ∑ = 5 [001] twist boundary in copper has been calculated.