density functional theory band structure calculation

Classical density functional theory uses a similar formalism to calculate the properties of non-uniform classical fluids.ĭespite the current popularity of these alterations or of the inclusion of additional terms, they are reported to stray away from the search for the exact functional. The development of new DFT methods designed to overcome this problem, by alterations to the functional or by the inclusion of additive terms, is a current research topic. interacting noble gas atoms) or where dispersion competes significantly with other effects (e.g. The incomplete treatment of dispersion can adversely affect the accuracy of DFT (at least when used alone and uncorrected) in the treatment of systems which are dominated by dispersion (e.g. Since, DFT has become an important tool for methods of nuclear spectroscopy such as Mössbauer spectroscopy or perturbed angular correlation, in order to understand the origin of specific electric field gradients in crystals.ĭespite recent improvements, there are still difficulties in using density functional theory to properly describe: intermolecular interactions (of critical importance to understanding chemical reactions), especially van der Waals forces (dispersion) charge transfer excitations transition states, global potential energy surfaces, dopant interactions and some strongly correlated systems and in calculations of the band gap and ferromagnetism in semiconductors. Computational costs are relatively low when compared to traditional methods, such as exchange only Hartree–Fock theory and its descendants that include electron correlation. However, DFT was not considered accurate enough for calculations in quantum chemistry until the 1990s, when the approximations used in the theory were greatly refined to better model the exchange and correlation interactions. DFT is among the most popular and versatile methods available in condensed-matter physics, computational physics, and computational chemistry.ĭFT has been very popular for calculations in solid-state physics since the 1970s. In the case of DFT, these are functionals of the spatially dependent electron density. Using this theory, the properties of a many-electron system can be determined by using functionals, i.e. Not to be confused with Discrete Fourier transform.ĭensity-functional theory ( DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (or nuclear structure) (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases.

Density functional theory band structure calculation