semiempirical approximation

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• chemical 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 …   Universalium

• SAM1 — SAM1, or Semiempirical ab initio Model 1 , is a semiempirical quantum chemistry method for computing molecular properties. It is an implementation the general Neglect of Differential Diatomic Overlap (NDDO) integral approximation, and is… …   Wikipedia

• Density functional theory — Electronic structure methods Tight binding Nearly free electron model Hartree–Fock method Modern valence bond Generalized valence bond Møller–Plesset perturbation theory …   Wikipedia

• Ab initio quantum chemistry methods — are computational chemistry methods based on quantum chemistry.[1] The term ab initio was first used in quantum chemistry by Robert Parr and coworkers, including David Craig in a semiempirical study on the excited states of benzene.[2][3] The… …   Wikipedia

• PM3 (chemistry) — PM3, or Parameterized Model number 3, is a semi empirical method for the quantum calculation of molecular electronic structure in computational chemistry. It is based on the Neglect of Differential Diatomic Overlap integral approximation. The PM3 …   Wikipedia

• NDDO — stands for neglect of diatomic differential overlap. The formalism was first introduced by John Pople and it is now the basis of most successful semiempirical methods. While INDO added all one centre two electron integrals to the CNDO/2 formalism …   Wikipedia

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• Nuclear binding energy — is the energy required to split a nucleus of an atom into its component parts. The component parts are neutrons and protons, which are collectively called nucleons. If the binding energy for the products is higher when light nuclei fuse, or when… …   Wikipedia

• Extended Huckel method — The extended Hückel method is a semiempirical quantum chemistry method, developed by Roald Hoffmann since 1963. [Hoffmann, R. An Extended Hückel Theory. I. Hydrocarbons. J. Chem. Phys 1963, 39 , 1397 1412. doi|10.1063/1.1734456] It is based on… …   Wikipedia

• Theoretical chemistry — involves the use of physics to explain or predict chemical phenomena. In recent years, it has consisted primarily of quantum chemistry, i.e., the application of quantum mechanics to problems in chemistry. Theoretical chemistry may be broadly… …   Wikipedia

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