hamiltonian function
101Variational principle — A variational principle is a principle in physics which is expressed in terms of the calculus of variations. According to Cornelius Lanczos, any physical law which can be expressed as a variational principle describes an expression which is self… …
102Constant of motion — In mechanics, a constant of motion is a quantity that is conserved throughout the motion, imposing in effect a constraint on the motion. However, it is a mathematical constraint, the natural consequence of the equations of motion, rather than a… …
103Hooke's atom — Hooke s atom, also known as harmonium, refers to an artificial helium like atom where the Coulombic electron nucleus interaction potential is replaced by a harmonic potential. [cite book |last=Lucjan |first=Piela |title=Ideas of Quantum Chemistry …
104Lippmann-Schwinger equation — The Lippmann Schwinger equation (named after Bernard A. Lippmann and Julian Schwinger) is of importance to scattering theory. The equation is: | psi^{(pm)} angle = | phi angle + frac{1}{E H 0 pm i epsilon} V |psi^{(pm)} angle. ,DerivationWe will… …
105Luke's variational principle — In fluid dynamics, Luke s variational principle is a Lagrangian variational description of the motion of surface waves on a fluid with a free surface, under the action of gravity. This principle is named after J.C. Luke, who published it in 1967 …
106Dynamical mean field theory — (DMFT) is a method to determine the electronic structure of strongly correlated materials. In such materials, the approximation of independent electrons, which is used in Density Functional Theory and usual band structure calculations, breaks… …
107Born-Oppenheimer approximation — In quantum chemistry, the computation of the energy and wavefunction of an average size molecule is a formidable task that is alleviated by the Born Oppenheimer (BO) approximation. For instance the benzene molecule consists of 12 nuclei and 42… …
108Quantum superposition — is the fundamental law of quantum mechanics. It defines the allowed state space of a quantum mechanical system.In Probability theory, every possible event has a positive number associated to it, the probability, which gives the chance that it… …
109Poisson bracket — In mathematics and classical mechanics, the Poisson bracket is an important operator in Hamiltonian mechanics, playing a central role in the definition of the time evolution of a dynamical system in the Hamiltonian formulation. In a more general… …
110Method of quantum characteristics — In quantum mechanics, quantum characteristics are phase space trajectories that arise in the deformation quantization through the Weyl Wigner transform of Heisenberg operators of canonical coordinates and momenta. These trajectories obey the… …
