perturbation of energy-level system
11Photon — This article is about the elementary particle of light. For other uses, see Photon (disambiguation). Photon Photons emitted in a coherent beam from a laser Composition Elementary particle …
12Laplace–Runge–Lenz vector — Throughout this article, vectors and their magnitudes are indicated by boldface and italic type, respectively; for example, left| mathbf{A} ight| = A. In classical mechanics, the Laplace–Runge–Lenz vector (or simply the LRL vector) is a vector… …
13Tight binding — Electronic structure methods Tight binding Nearly free electron model Hartree–Fock method Modern valence bond Generalized valence bond Møller–Plesset perturbat …
14Density of states — Condensed matter physics Phases · Phase tr …
15chemical bonding — ▪ chemistry Introduction any of the interactions that account for the association of atoms into molecules, ions, crystals, and other stable species that make up the familiar substances of the everyday world. When atoms approach one another …
16Electronic band structure — In solid state physics, the electronic band structure (or simply band structure) of a solid describes ranges of energy that an electron is forbidden or allowed to have. It is due to the diffraction of the quantum mechanical electron waves in the… …
17fusion reactor — Physics. a reactor for producing atomic energy by nuclear fusion. Cf. reactor (def. 4). * * * Introduction also called fusion power plant or thermonuclear reactor a device to produce electrical power from the energy released in a nuclear… …
18Quantum mechanics — For a generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. Quantum mechanics …
19Raman scattering — or the Raman effect (pronounced: IPA| [rə.mən] ) is the inelastic scattering of a photon. Discovered By Dr. C.V. Raman in liquids and by Grigory Landsberg and Leonid Mandelstam in crystals.When light is scattered from an atom or molecule, most… …
20Nuclear shell model — In nuclear physics and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels.[1] The first shell model was proposed… …
