Titlebook: Quantum Chemistry; Fundamentals to Appl Tamás Veszprémi,Miklós Fehér Book 1999 Springer Science+Business Media New York 1999 chemical react

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Molecular Structuretick fully to the Born—Oppenheimer approximation, we would need to follow a more exact but also more difficult path: solving the Schrödinger equation containing both electronic and vibrational terms. Since the latter approach can be realistically achieved only in the case of molecules with at most a handful of atoms, we will not deal with it here.

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Fundamentals of Group Theoryymmetry is essential for understanding many branches of theoretical chemistry and spectroscopy. It can, for example, help us to understand spectroscopic selection rules, guide us in molecular orbital theory, or make understanding chemical reactions easier. Very often it provides strikingly simple an

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Postulates of Quantum Mechanicshat mechanics, thermodynamics, and electrodynamics were complete and consistent theories and that only a few minor controversies required further explanation. These included black body radiation, Compton and photoelectric effects, the existence of line spectra (as opposed to continuum) and X-ray rad

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Playing with the Schrödinger Equationthe appropriate Hamiltonian operator for the problem at hand. The kinetic energy operator is universal; it depends only on the number of particles in the system. The potential energy function is more characteristic of the system, and the difficulty of solution depends on its form. It is only possibl

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Methods of Solution widely used mathematical techniques of the solution: variation and perturbation theory. Both are powerful tools in the practical calculation of molecular properties. There are many different variations of these methods, and we will restrict our brief discussion to the simplest cases.

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The Hartree-Fock Method and Its Consequencesns for calculating the energy (and other properties) of the wave function? We write down the expectation value of the energy, based on Eqs. (4.14)-(4.16):.where Ф is the Slater determinant of the system under study, ..(.) is the one-electron operator from (4.15), and ..(.) = (../..), the two-electro

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Beyond the Hartree-Fock Methodincreased, the asymptote for the calculated physical or chemical data is not the experimental value, but the Hartree–Fock limit. Remember that the energy difference between the HF limit and the exact nonrelativistic solution of the Schrödinger equation is called the . This energy contribution arises