Development of electronic structure theory using the characteristics of Kohn-Sham potential

Abstract

The density functional theory is an electronic structure calculation method widely used in chemical, physical and material science research. Since the Kohn-Sham density functional calculation uses an effective one-electron equation to get information of a multi-electron system, not only is it possible to obtain accurate results with a relatively small computational cost but also provides a molecular orbital description familiar to the chemist. However, conventional exchange-correlation functionals are not possible to give the correct orbital because of a self-interaction error, more generally a delocalization error. In this dissertation, we introduce the characteristics of the Kohn-Sham exchange-correlation potential and orbitals. Based on this we propose two different electronic structure calculation methods. First, we investigate the characteristics of the Kohn-Sham orbitals obtained by using a local exact-exchange potential and introduce the new excited state calculation method using those orbital. Finally, we introduce a localized orbital scaling correction method which utilizes orbital-dependent correction terms to solve the delocalization error.