the nearly free electron model (or NFE model and quasi-free electron model) is a quantum mechanical model of physical properties of electrons that can...

In solid-state physics, the free electron model is a quantum mechanical model for the behaviour of charge carriers in a metallic solid. It was developed...

with two complementary models for electrons in solids.: 161  The first one is the nearly free electron model, in which the electrons are assumed to move...

band structure Nearly-free electron model Bloch's theorems Kronig-Penney model Fermi surface Wannier function Hubbard model t-J model Effective mass Anderson's...

Independent electron approximation Lone pair or free electron pair Nearly free electron model Orbital angular momentum of free electrons Unpaired electron This...

potential of the lattice in this free electron model must be weak because otherwise the electrons wouldn't be free. The strength of the scattering mainly...

electron model and its further extension, the nearly free electron model. In both models, the electrons are seen as a gas traveling through the structure...

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

surface. The nearly free electron model adapts the Fermi gas model to consider the crystal structure of metals and semiconductors, where electrons in a crystal...

energy within modern orbital-free density functional theory. Working independently, Thomas and Fermi used this statistical model in 1927 to approximate the...

of electron correlation effects into the methods. Within the framework of Hartree–Fock calculations, some pieces of information (such as two-electron integrals)...

insulators. The nearly free electron model is a modification of the free electron model which includes a weak periodic perturbation meant to model the interaction...

the dispersion relation. Models of solids and crystals: Tight-binding model Free electron model Nearly free electron model Kittel, Introduction to Solid...

particles. Usual models are the free electron model and the nearly free electron model. In the appropriate systems, the free electron pressure can be calculated;...

Electronic band structure Nearly free electron model Periodic boundary conditions Symmetries in quantum mechanics Tight-binding model Wannier function Bloch...

theory similar to Lewis' only his model assumed complete transfers of electrons between atoms, and was thus a model of ionic bonding. Both Lewis and Kossel...

Perdew–Burke–Ernzerhof exchange model (a direct generalized gradient parameterization of the free-electron gas with no free parameters); however, this is...

field (SCF), method. They add electron correlation which is a more accurate way of including the repulsions between electrons than in the Hartree–Fock method...

inverse of the typical separation) The electron gas dielectric function in the simplest Thomas–Fermi screening model for a wave vector q {\displaystyle q}...

which valence bond theory cannot explain. In molecular orbital theory, electrons in a molecule are not assigned to individual chemical bonds between atoms...

crystals as null. It is a requirement for both the free electron model and the nearly-free electron model, where it is used alongside Bloch's theorem. In...

Fentress, a military airport in Virginia, USA (by FAA LID code) Nearly free electron model Non-formal education New French Extremity Nordisk familjebok ecology...

are more computationally convenient, and provides a way to calculate all-electron properties from these smooth wavefunctions. This approach is somewhat reminiscent...

electromagnetic field so electrons are subject to a regular potential inside the lattice. It is a generalization of the free electron model, which assumes zero...

law). The existence of a non-zero quantum defect was attributed to electron–electron repulsion, which clearly does not exist in the isolated hydrogen atom...

problems. Diffusion Monte Carlo: The most common high-accuracy method for electrons (that is, chemical problems), since it comes quite close to the exact...

muffin-tin approximation. It is a method to approximate the energy states of an electron in a crystal lattice. The basic approximation lies in the potential in...

and binding energy of a metal. Various models are applicable, the simplest being the nearly free electron model. Modern methods such as density functional...

Thomas–Fermi model. Orbital-free density functional theory is, at present, less accurate than Kohn–Sham density functional theory models, but it has the...

known as the uniform electron gas (UEG) or homogeneous electron gas (HEG), is a quantum mechanical model of interacting free electrons in a solid where the...