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... Abstract-The unified theory has been generalized for the case of upper and lower state interaction by introducing a more compact tetradic notation. The general result is then applied to the Stark broadening of h>drogen. The thermal average of the time development operator for upper and lower state i ...
Solvation of electronically excited I2-
Solvation of electronically excited I2-

... interaction potential at short range, intermolecular 1/R12 repulsive terms must be added to the potential. However, since these depend only on the nuclear coordinates they can be treated separately from the electronic Hamiltonian.) Either the experimentally determined’* or ab initio BornOppenheimer ...
Hydrogen atom in phase space: the Wigner representation
Hydrogen atom in phase space: the Wigner representation

... atom has been investigated recently using the Kirkwood–Rihaczek phase space representation, which is easier because it involves only products of the momentum and position wavefunctions with a proper phase [8]. This rather vexing situation regarding the analytical form of Wigner functions for the hyd ...
Operator Algebras and Index Theorems in Quantum Field Theory
Operator Algebras and Index Theorems in Quantum Field Theory

... charge is discussed Strominger, Vafa and others. We illustrate our discussion by the work of Carlip. Yet we use here only the value of the central charge and not Cardy’s formula nor the boundary term of the energy. ...
F.Y. B.Sc. - Chemistry
F.Y. B.Sc. - Chemistry

These notes
These notes

The Schrödinger Wave Equation
The Schrödinger Wave Equation

Chapter 5 Wave Mechanics
Chapter 5 Wave Mechanics

Elementary Quantum Mechanics
Elementary Quantum Mechanics

Bonding and Molecular Structure: Orbital Hybridization and
Bonding and Molecular Structure: Orbital Hybridization and

Pulse-train control of photofragmentation at constant field energy
Pulse-train control of photofragmentation at constant field energy

... In this limit, according to Eq. (2), only the frequency distribution of the laser field is reflected in the excitation probability, i.e., via |A(ω)|2 , where ω = E/¯. A short laser pulse generates products with a distribution of energies selected according to |A(ω)|2 . The outcome which is obtained ...
Chapter 10 Chemical Bonding Theories
Chapter 10 Chemical Bonding Theories

Orbital ice: An exact Coulomb phase on the diamond lattice
Orbital ice: An exact Coulomb phase on the diamond lattice

Electronic Structure of Clusters
Electronic Structure of Clusters

... instead with an average field12,13 (see Hartree – Fock Theory). The error incurred by this treatment of the electron correlation problem generally becomes more significant for systems with low-lying electronic states, as are commonly found in transition metal compounds. Density functional theory14 ( ...
Can the Wave Function in Configuration Space Be Replaced by
Can the Wave Function in Configuration Space Be Replaced by

... Indeed, even Bohm himself seems to have found this aspect of his theory (the idea of a physically real field living in an abstract configuration space) to be somewhat indigestible: “...a serious problem confronts us when we extend the theory ... to the treatment of more than one electron. This diffi ...
Physics 139B Solutions to Homework Set 4 Fall 2009 1. Liboff
Physics 139B Solutions to Homework Set 4 Fall 2009 1. Liboff

Ab Initio correlated all electron Dirac
Ab Initio correlated all electron Dirac

Background Material
Background Material

Localized shocks Please share
Localized shocks Please share

... Building on this work and ideas of Swingle [21], Maldacena [20] suggested that the interior could be understood as a refined type of tensor network describing the state of the dual gauge theory. According to this picture, the overall length of the interior is proportional to size of the minimal tens ...
Chapter 2. Model Problems That Form Important Starting Points
Chapter 2. Model Problems That Form Important Starting Points

MOLECULAR ORBITAL THEORY AND BONDING NOTES
MOLECULAR ORBITAL THEORY AND BONDING NOTES

Low-Temperature Phase Diagrams of Quantum Lattice
Low-Temperature Phase Diagrams of Quantum Lattice

Quantities in Chemistry
Quantities in Chemistry

... each subject lecture. Although great care is taken to ensure that these materials are mistake free, an error may appear from time to time. If you believe that there is an error in these notes or solutions, please let us know asap ([email protected]). Errors, as well as additional advice, clarificati ...
Variational Monte Carlo studies of Atoms - DUO
Variational Monte Carlo studies of Atoms - DUO

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Coupled cluster

Coupled cluster (CC) is a numerical technique used for describing many-body systems. Its most common use is as one of several post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry. It essentially takes the basic Hartree–Fock molecular orbital method and constructs multi-electron wavefunctions using the exponential cluster operator to account for electron correlation. Some of the most accurate calculations for small to medium-sized molecules use this method.The method was initially developed by Fritz Coester and Hermann Kümmel in the 1950s for studying nuclear physics phenomena, but became more frequently used when in 1966 Jiři Čížek (and later together with Josef Paldus) reformulated the method for electron correlation in atoms and molecules. It is now one of the most prevalent methods in quantum chemistry that includes electronic correlation.CC theory is simply the perturbative variant of the Many Electron Theory (MET) of Oktay Sinanoğlu, which is the exact (and variational) solution of the many electron problem, so it was also called ""Coupled Pair MET (CPMET)"". J. Čížek used the correlation function of MET and used Goldstone type perturbation theory to get the energy expression while original MET was completely variational. Čížek first developed the Linear-CPMET and then generalized it to full CPMET in the same paper in 1966. He then also performed an application of it on benzene molecule with O. Sinanoğlu in the same year. Because MET is somewhat difficult to perform computationally, CC is simpler and thus, in today's computational chemistry, CC is the best variant of MET and gives highly accurate results in comparison to experiments.
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