Note on an Approximation Treatment for Many-Electron Systems
Chr. Møller,Milton S. Plesset +1 more
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In this article, a perturbation theory for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation was developed, and it was shown by this development that the first order correction for the energy and the charge density of the system is zero.Abstract:
A perturbation theory is developed for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation. It is shown by this development that the first order correction for the energy and the charge density of the system is zero. The expression for the second-order correction for the energy greatly simplifies because of the special property of the zero-order solution. It is pointed out that the development of the higher approximation involves only calculations based on a definite one-body problem.read more
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How Strong Is an Agostic Bond? Direct Assessment of Agostic Interactions Using the Generalized Compliance Matrix†
TL;DR: In this article, the strength of α-agostic bond in CH2TiHF has been evaluated using the generalized compliance matrix from HF (Hartree−Fock), MP2 (second-order Moller−Plesset perturbation), CCSD(T) (coupled clus...
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The VCI-P code: an iterative variation–perturbation scheme for efficient computations of anharmonic vibrational levels and IR intensities of polyatomic molecules
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Computational determination of aqueous pKa values of protonated benzimidazoles (part 1).
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Consistent Theoretical Description of 1,3-Dipolar Cycloaddition Reactions
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TL;DR: The cycloaddition reactions of 18 1,3-dipolar molecules to ethylene and acetylene have been reinvestigated by quantum chemical methods that are based on a second-order perturbation treatment of electron correlation and it is found that SCS-MP2 and the new perturbative B2-PLYP density functional provide accurate reaction barriers and outperform MP2 as well as standard density functionals such as B3-LYP.
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Spectra and structure of silicon‐containing compounds. XXXVI—Raman and infrared spectra, conformational stability, ab initio calculations and vibrational assignment of ethyldibromosilane
Gamil A. Guirgis,Peter Klaboe,Shiyu Shen,D. L. Powell,Alytis Gruodis,Valdemaras Aleksa,Claus J. Nielsen,Jing Tao,Chao Zheng,James R. Durig +9 more
TL;DR: In this article, the Raman spectrum of liquid ethyldibromosilane, CH3CH2SiHBr2, was recorded at various temperatures between 298 and 218 K, and the spectrum of the crystal was obtained at 210 K from a sample sealed in a capillary.