Place: Computational Materials Science Workshop, Domburg, The Netherlands
David Pettifor, Department of Materials, University of Oxford, Oxford, United Kingdom
Tight-binding (TB) parameters may be obtained from density functional theory (DFT) by projecting the DFT wave functions on the TB minimal basis. We create a comprehensive database of TB parameters for all dimers of sp- and sd-valent atoms using the Harris-Foulkes wave function as reference. We demonstrate that the Hamiltonian matrix elements of the intrinsically non-orthogonal and the Loewdin-transformed orthogonal TB model, as well as the overlap matrix elements, can be satisfactorily fitted using a single functional form. This enables us to compute the bond energy, promotion energy and repulsive energy within the TB bond model and to carry out a systematic analysis of hybridization and screening effects. We extract trends of the TB parameters across the periodic table and verify the quality of the parameterizations for bulk structures.