The muffin-tin approximation is a shape approximation of the potential well in a crystal lattice. It is most commonly employed in quantum mechanical simulations...

The GW approximation (GWA) is an approximation made in order to calculate the self-energy of a many-body system of electrons. The approximation is that...

derivation based on the Kohn and Rostoker variational method, the muffin-tin approximation was used. Later calculations are done with full potentials having...

about strongly correlated material the tight binding approach is basic approximation because highly localized electrons like 3-d transition metal electrons...

The model is closely related to the more conceptual empty lattice approximation. The model enables understanding and calculation of the electronic band...

these approaches is to provide a reliable solution (or an accurate approximation) of the quantum many-body problem. The diverse flavors of quantum Monte...

disordered system. The simplest form of this approximation centers non-overlapping spheres (referred to as muffin tins) on the atomic positions. Within these...

enough for calculations in quantum chemistry until the 1990s, when the approximations used in the theory were greatly refined to better model the exchange...

correct only in the limit of an infinite nuclear charge. Using the approximation for realistic systems yields poor quantitative predictions, even failing...

The empty lattice approximation is a theoretical electronic band structure model in which the potential is periodic and weak (close to constant). One...

spirit to the muffin-tin approximation), computing the integral of r × J(r) inside each sphere, and summing the contributions. This approximation neglects...

practice, instead of deriving approximations for interacting kinetic energy, much effort was devoted to deriving approximations for non-interacting (Kohn–Sham)...

the nonrelativistic Schrödinger equation within the Born–Oppenheimer approximation for a quantum chemical multi-electron system. Mathematically, configuration...

809. Gyorffy, B. L. (1972-03-15). "Coherent-Potential Approximation for a Nonoverlapping-Muffin-Tin-Potential Model of Random Substitutional Alloys". Physical...

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

in particular avoid the muffin-tin approximation. The second one uses the Green formalism (multiple scattering) on a muffin- tin potential. This approach...

pertubation theory Møller, Christian; Plesset, Milton S. (1934). "Note on an Approximation Treatment for Many-Electron Systems" (PDF). Phys. Rev. 46 (7): 618–622...

physics and chemistry, the Hartree–Fock (HF) method is a method of approximation for the determination of the wave function and the energy of a quantum...

electron model Tight binding Muffin-tin approximation k·p perturbation theory Empty lattice approximation GW approximation Korringa–Kohn–Rostoker method...

all previous times. Consequently, the development of time-dependent approximations for the implementation of TDDFT is behind that of DFT, with applications...

chemistry methods are based on the Hartree–Fock formalism, but make many approximations and obtain some parameters from empirical data. They are very important...

Evan O. Kane). According to quantum mechanics (in the single-electron approximation), the quasi-free electrons in any solid are characterized by wavefunctions...

functions. The PAW method is typically combined with the frozen core approximation, in which the core states are assumed to be unaffected by the ion's...

electron model Tight binding Muffin-tin approximation k·p perturbation theory Empty lattice approximation GW approximation Korringa–Kohn–Rostoker method...

optimization and frequency calculation. Additionally, the frozen-core approximation is made for the initial MP2 optimization, whereas G2 usually uses the...

1964; (iii) Brown, Robert G.; Ciftan, Mikael (1984). "A generalized non-muffin-tin theory of band structure". International Journal of Quantum Chemistry...

equation and its set of solutions: For molecules, the Born–Oppenheimer approximation is inherently assumed. The true wavefunction should also be a function...

within the Born–Oppenheimer approximation (although schemes have also been drawn up to work without the BO approximation). One possible improvement to...

electron model Tight binding Muffin-tin approximation k·p perturbation theory Empty lattice approximation GW approximation Korringa–Kohn–Rostoker method...

electron model Tight binding Muffin-tin approximation k·p perturbation theory Empty lattice approximation GW approximation Korringa–Kohn–Rostoker method...