Density Functional Theory (DFT)
Density Functional Theory (DFT)
Assist. Prof. Bilal Kamal Ahmed Al-Rawi - Department of physics
(DFT) is the quantum mechanical modeling method applied in physics and chemistry to investigate the electronic structure (principally the ground state) of a many-body systems, in particular atoms, molecules, and the condensed phases. In this theory, the properties of a many-electron system can be specified by using functional, which in this case is a spatially dependent electron density. Hence, the name to the density functional theory comes from the employ of functionals of the electron density. DFT is among the most popular and many-sided methods available in condensed-matter physics, computational physics, and computational chemistry . DFT is a successful approach for attributing the ground-state properties of metals, semiconductors, and insulators. DFT is applicable not only to bulk materials but also to complex materials, such as proteins and carbon nanotubes. Although DFT can effectively attribute the properties of ground state, practical applications of DFT are based on exchange–correlation potential approximations, which show superior accuracy to HF theory (ab-initio and semi-empirical approximations). The exchange–correlation potential characterizes the effects of the Pauli Exclusion Principle and the Coulomb potential beyond the electrostatic interaction of electrons. Determining the exact exchange–correlation potential suggests that the many body problems are solved exactly; this condition is clearly unfeasible in solids.