Optimized LCAO Method and the Electronic Structure of Extended Systems

ISBN-13: 9783662025642 / Angielski / Miękka / 2012 / 221 str.

Helmut Eschrig

Opis

Theoretical and numerical details of an optimized LCAO (linear combination of atomic orbitals) method for the calculation of self-consistent bandstructures are given together with a variety of examples. The method will be a valuable tool both for researchers engaged in calculations and for scientists looking for numerical results of self-consistent bandstructure calculations. The presentation starts with an introduction to the modern many-body theory of electronic bandstructure. The essentials of the representation with a non-orthogonal basis and the usual tight-binding variants are critically reviewed. A variational approach to the optimization of atom-like basis orbitals is described together with an SCF procedure for band calculations. Complete numerical and graphic results for all elementary metals from lithium to zinc are given.

Spis treści

Content.- 1. Introduotion.- 2. The LCAO formalism.- 3. Optimization of the basis.- 4. Wannier funotions.- 5. The local basis representations of the electron density.- 6. Simplex methods for k-epaos integrations in d dimensions.- 7.. Potential oonstruotion and iteration.- Appendix 1. Spherical harmonics and their transformations.- Appendix 2. Some useful theorems on basis function expansions.- Appendix 3. Results of DFT-LCAO band structure calculations for element metals.- References.