• spirit of the original HK theorems, is orbital-free density functional theory (OFDFT), in which approximate functionals are also used for the kinetic energy...
    80 KB (10,626 words) - 22:19, 9 May 2025
  • orbital-free density functional theory (OFDFT) is a quantum mechanical approach to electronic structure determination which is based on functionals of...
    14 KB (2,156 words) - 22:33, 11 June 2025
  • Time-dependent density-functional theory (TDDFT) is a quantum mechanical theory used in physics and chemistry to investigate the properties and dynamics...
    16 KB (2,496 words) - 13:43, 2 June 2025
  • molecular orbitals – as linear combinations of atomic orbitals (LCAO). These approximations are made by applying the density functional theory (DFT) or...
    28 KB (3,710 words) - 11:02, 31 May 2025
  • 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...
    37 KB (4,835 words) - 02:03, 12 May 2025
  • 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...
    15 KB (2,457 words) - 11:40, 25 May 2025
  • alternative to Hartree–Fock calculations used in some cases is density functional theory, which treats both exchange and correlation energies, albeit approximately...
    31 KB (4,739 words) - 21:08, 25 May 2025
  • 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...
    15 KB (1,922 words) - 21:45, 25 May 2025
  • many-body effects encoded in the wave function, going beyond mean-field theory. In particular, there exist numerically exact and polynomially-scaling algorithms...
    10 KB (1,140 words) - 04:47, 13 June 2025
  • 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...
    23 KB (2,899 words) - 04:03, 13 June 2025
  • {\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]}...
    8 KB (1,098 words) - 15:25, 13 January 2024
  • combinations of either atomic orbitals, delocalized atomic orbitals (Coulson-Fischer theory), or even molecular orbital fragments. Although this is often...
    20 KB (2,715 words) - 06:18, 23 May 2025
  • 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...
    9 KB (1,346 words) - 21:35, 11 March 2024
  • Thumbnail for Tight binding
    Anderson's rule Dynamical theory of diffraction Solid state physics Linear combination of atomic orbitals molecular orbital method (LCAO) Holstein–Herring...
    35 KB (7,469 words) - 19:10, 5 June 2025
  • Conversely, the density determines the wave function modulo up to a phase factor, providing the formal foundation of density functional theory. According to...
    16 KB (2,301 words) - 18:48, 21 November 2024
  • Optimized effective potential method (category Density functional theory)
    Kohn-Sham (KS) density functional theory (DFT) is a method to determine the potentials as functional derivatives of the corresponding KS orbital-dependent...
    10 KB (1,413 words) - 03:58, 10 May 2025
  • 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...
    11 KB (1,454 words) - 21:07, 23 April 2025
  • 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...
    6 KB (635 words) - 06:08, 3 June 2021
  • pseudopotential and linear augmented-plane-wave methods, and allows for density functional theory calculations to be performed with greater computational efficiency...
    8 KB (1,149 words) - 17:23, 27 June 2024
  • GW approximation (category Quantum field theory)
    homogeneous or uniform electron gas which is characterized by an electron density or equivalently the average electron-electron separation or Wigner–Seitz...
    10 KB (1,298 words) - 23:59, 24 May 2025
  • 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...
    28 KB (4,353 words) - 02:08, 11 December 2024
  • 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...
    6 KB (844 words) - 13:36, 5 June 2025
  • Thumbnail for John Perdew
    analogue to the Kohn-Sham equations for Orbital-free density functional theory. Visualizing DFT functionals to be a succession of ladder steps, Perdew...
    12 KB (1,217 words) - 02:47, 9 March 2025
  • chemistry, natural resonance theory (NRT) is an iterative, variational functional embedded into the natural bond orbital (NBO) program, commonly run in...
    32 KB (3,001 words) - 13:47, 22 May 2025
  • 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 ...
    12 KB (1,975 words) - 08:09, 19 December 2024
  • reference states of molecules in cases where Hartree–Fock and density functional theory are not adequate (e.g., for molecular ground states which are...
    8 KB (1,120 words) - 01:27, 1 October 2024
  • Thumbnail for Emily A. Carter
    for orbital-free density functional theory (OF-DFT) that can be applied to large numbers of atoms as well as embedded correlated wavefunction theory for...
    28 KB (2,788 words) - 10:34, 3 June 2025
  • Thumbnail for Mu (letter)
    defines IgM type Antibodies In pharmacology: an important opiate receptor In orbital mechanics: Standard gravitational parameter of a celestial body, the product...
    14 KB (1,670 words) - 13:00, 3 June 2025
  • Jellium (category Density functional theory)
    electronic density. This property lends it to a treatment within density functional theory; the formalism itself provides the basis for the local-density approximation...
    19 KB (2,922 words) - 16:53, 15 March 2025
  • Gotthard; Joswig, Jan-Ole (2012). "Density-functional tight binding—an approximate density-functional theory method". WIREs Computational Molecular Science...
    12 KB (1,419 words) - 19:32, 25 May 2025