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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On the hydrogen bond nature of the C–H⋯F interactions in molecular crystals. An exhaustive investigation combining a crystallographic database search and ab initio theoretical calculations
Emiliana D'Oria,Juan J. Novoa +1 more
TL;DR: In this paper, the authors investigated the nature of C-H⋯F interactions in molecular crystals and found that when the two interacting fragments involved in the interaction are neutral, they behave as weak hydrogen bonds: they have an interaction energy around −0.4 kcal mol−1, dominated by the electrostatic and dispersion components.
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Effects of basis set and electron correlation on the calculated interaction energies of hydrogen bonding complexes: MP2/cc-pV5Z calculations of H2O–MeOH,H2O–Me2O,H2O–H2CO, MeOH–MeOH, and HCOOH–HCOOH complexes
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Rotational spectra and structures of three hydrogen-bonded complexes between formic acid and water
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