spirit of the original HK theorems, is orbital-free density functional theory (OFDFT), in which approximate functionals are also used for the kinetic energy...

orbital-free density functional theory (OFDFT) is a quantum mechanical approach to electronic structure determination which is based on functionals of...

Time-dependent density-functional theory (TDDFT) is a quantum mechanical theory used in physics and chemistry to investigate the properties and dynamics...

molecular orbitals – as linear combinations of atomic orbitals (LCAO). These approximations are made by applying the density functional theory (DFT) or...

calculated using density-functional theory (DFT), which is not a model but rather a theory, i.e., a microscopic first-principles theory of condensed matter...

Thomas–Fermi theory is also used as a component in more sophisticated density approximation to the kinetic energy within modern orbital-free density functional theory...

many-body effects encoded in the wave function, going beyond mean-field theory. In particular, there exist numerically exact and polynomially-scaling algorithms...

In chemistry, valence bond (VB) theory is one of the two basic theories, along with molecular orbital (MO) theory, that were developed to use the methods...

alternative to Hartree–Fock calculations used in some cases is density functional theory, which treats both exchange and correlation energies, albeit approximately...

to what MP pertubation theory is in HF theory is Görling-Levy (GL) pertubation theory in Kohn-Sham (KS) density functional theory (DFT). Electron correlation...

analogue to the Kohn-Sham equations for Orbital-free density functional theory. Visualizing DFT functionals to be a succession of ladder steps, Perdew...

In solid-state physics, the nearly free electron model (or NFE model and quasi-free electron model) is a quantum mechanical model of physical properties...

combinations of either atomic orbitals, delocalized atomic orbitals (Coulson-Fischer theory), or even molecular orbital fragments. Although this is often...

band), with an extremum at k = 0, and with no spin–orbit coupling, the result of k·p perturbation theory is (to lowest nontrivial order): u n , k = u n ...

chemistry, natural resonance theory (NRT) is an iterative, variational functional embedded into the natural bond orbital (NBO) program, commonly run in...

Anderson's rule Dynamical theory of diffraction Solid state physics Linear combination of atomic orbitals molecular orbital method (LCAO) Holstein–Herring...

pseudopotential and linear augmented-plane-wave methods, and allows for density functional theory calculations to be performed with greater computational efficiency...

bond theory and molecular orbital theory, whilst avoiding many of their weaknesses. For example, unlike the widely used Hartree–Fock molecular orbital method...

determinants where the electron in orbital i has been excited to orbital a and the electron in orbital j has been excited to orbital b, etc. In this way we generate...

perturbation theory (GLPT) in Kohn–Sham (KS) density functional theory (DFT) is the analogue to what Møller–Plesset perturbation theory (MPPT) is in Hartree–Fock...

by the number of spin orbitals that are swapped with virtual orbitals from the Hartree–Fock determinant. If only one spin orbital differs, we describe...

Conversely, the density determines the wave function modulo up to a phase factor, providing the formal foundation of density functional theory. According to...

homogeneous or uniform electron gas which is characterized by an electron density or equivalently the average electron-electron separation or Wigner–Seitz...

the solution of a complicated many-electron problem, but the density functional theory of Walter Kohn makes it possible to reduce it to the solution...

the linear muffin-tin orbital method (LMTO) and various Green's function methods. One application is found in the variational theory developed by Jan Korringa...

calculations of fragments and their dimers, such as Hartree–Fock, Density functional theory (DFT), Multi-configurational self-consistent field (MCSCF), time-dependent...

{\displaystyle [\mathbf {k} ,\mathbf {k} +d\mathbf {k} ]} increases. The density of states in an energy interval [ E , E + d E ] {\displaystyle [E,E+dE]}...

reference states of molecules in cases where Hartree–Fock and density functional theory are not adequate (e.g., for molecular ground states which are...

Kohn-Sham (KS) density functional theory (DFT) is a method to determine the potentials as functional derivatives of the corresponding KS orbital-dependent...

Gotthard; Joswig, Jan-Ole (2012). "Density-functional tight binding—an approximate density-functional theory method". WIREs Computational Molecular Science...