الرئيسية » أرشيف الوسم : quantum

أرشيف الوسم : quantum

absolute reaction rate theory

absolute reaction rate theory a theory that sets out to predict the absolute reaction rate of a chemical reaction from the quantum mechanical description of the potential energy changes during the interaction between chemical species. It is most widely drawn upon in applying thermodynamic reasoning to equilibria between reactants in …

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Quantum numbers

Quantum numbers: These are numbers which are used to specify the location and energy of an electron and size, shape and orientation of the orbital to which a particular electron belongs. Principal or total quantum number (n): This quantum number is identical with that used in Bohr Sommer field theory. …

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Quantization

Quantization: means that a quantity does not vary continuously. The energy of an electron in an atom cannot have any arbitrary value but only certain characteristic values. ­A definite quantum of energy is accepted while moving from lower to higher energy level or lost while moving from higher to lower …

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adiabatic approximation

adiabatic approximation An ap­proximation used in quantum me­chanics when the time dependence of parameters, such as the internuclear distance between atoms in a molecule, is slowly varying. This ap­proximation means that the solution of the Schrodinger equation at one time goes continuously over to the solution at a later time. …

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ab-initio calculation

A method of calculating atomic and molecular structure directly from the first principles of quantum mechanics, without using quantities derived from experiment (such as ionization energies found by spectroscopy) as parameters. Ab-initio calculations require a large amount of numerical computation; the amount of computing time required increases rapidly as the size …

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