Note on an Approximation Treatment for Many-Electron Systems
Chr. Møller,Milton S. Plesset +1 more
Reads0
Chats0
TLDR
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
Citations
More filters
Journal ArticleDOI
Hydrogen Bond versus Anti-Hydrogen Bond: A Comparative Analysis Based on the Electron Density Topology
TL;DR: In this article, the electron density of C−H···π complexes has been determined for a series of H−Hπ complexes, which exhibit either anti-H bond or normal H bond character.
Journal ArticleDOI
In situ synthesis, electrochemical and quantum chemical analysis of an amino acid-derived ionic liquid inhibitor for corrosion protection of mild steel in 1M HCl solution
Elaheh Kowsari,S.Y. Arman,M.H. Shahini,H. Zandi,Ali Ehsani,Reza Naderi,A. PourghasemiHanza,M. Mehdipour +7 more
TL;DR: In this paper, an amino acid-derived ionic liquid inhibitor, namely tetra-n-butyl ammonium methioninate, was synthesized and the role this inhibitor for corrosion protection of mild steel exposed to 1.0 M HCl was investigated using electrochemical, quantum and surface analysis.
Journal ArticleDOI
How much double excitation character do the lowest excited states of linear polyenes have
TL;DR: In this paper, it was shown that for short polyenes the lowest excited 2 1 A g - and 1 1 B u - states can be classified as doubly excited, whereas the ground state is essentially represented by the (ground-state) HF determinant.
Journal ArticleDOI
Ab initio Hartree–Fock and density functional theory investigations on the conformational stability, molecular structure and vibrational spectra of 7-acetoxy-6-(2,3-dibromopropyl)-4,8-dimethylcoumarin molecule
TL;DR: In this article, a conformational analysis of 7-acetoxy-6-(2,3-dibromopropyl)-4,8-dimethylcoumarin molecule (abbreviated as 7ADDC) was performed by using ab initio Hartree-Fock (HF) method with 3-21G as the basis set to find the most stable form of 7ADdc.
Journal ArticleDOI
Molecular surface electrostatic potentials in relation to noncovalent interactions in biological systems
TL;DR: Several applications will be discussed, including initial qualitative studies of dioxins, a series of anticonvulsants and some tetracyclines, the nucleotide bases, and a recent quantitative treatment of the anti-HIV activities of three groups of reverse transcriptase inhibitors.