Titlebook: Computational Chemistry; Introduction to the Errol G. Lewars Textbook 20112nd edition Springer Science+Business Media B.V. 2011 ab initio

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An Outline of What Computational Chemistry Is All About,ar mechanics, ab initio, semiempirical and density functional methods, and molecular dynamics. Computational chemistry is widely used in the pharmaceutical industry to explore the interactions of potential drugs with biomolecules, for example by docking a candidate drug into the active site of an en

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The Concept of the Potential Energy Surface,e energy of a molecule (or a collection of molecules) and its geometry. The Born–Oppenheimer approximation says that in a molecule the nuclei are essentially stationary compared to the electrons. This is one of the cornerstones of computational chemistry because it makes the concept of molecular sha

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Molecular Mechanics,of terms involving bond stretching, angle bending, dihedral angles and nonbonded interactions. Giving these terms explicit mathematical forms constitutes devising a forcefield, and giving actual numbers to the constants in the forcefield constitutes parameterizing the field. An example is given of t

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Ab initio Calculations,n the simplest approach, the Hartree–Fock method, the total molecular wavefunction Ψ is approximated as a Slater determinant composed of occupied spin orbitals. To use these in practical calculations the spatial orbitals are approximated as a linear combination (a weighted sum) of basis functions. E

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Semiempirical Calculations,ted diagonalization of the Fock matrix refines the wavefunction and molecular energy. These calculations are much faster than ab initio ones, mainly because the number of integrals to be dealt with is greatly reduced by ignoring some and approximating others with the help of experimental quantities,