Löwdin P-O. Quantum theory of many-particle systems. I. Physical interpretations bymeans of density matrices, natural spin-orbitals, and convergence problems in the method of configurational interaction. Phys. Rev. 97:1474-89, 1955
ثبت نشده
چکیده
reduced density matrices of value in calculating the expectation values of various physical quantities is given. The eigenfunctions to the first-order density matrix or natural spin-orbitals have the property that, in the method of configurational interaction for calculating wave functions, they give the most rapid convergence. [The SCIa indicates that this paper has been cited in over 770 publications.]
منابع مشابه
Quantum Chemical Modeling of N-(2-benzoylphenyl)oxalamate: Geometry Optimization, NMR, FMO, MEP and NBO Analysis Based on DFT Calculations
In the present work, the quantum theoretical calculations of the molecular structure of the (N-(2-benzoylphenyl) oxalamate has been investigated and are evaluated using Density Functional Theory (DFT). The geometry of the title compound was optimized by B3LYP method with 6-311+G(d) basis set. The theoretical 1H and 13C NMR chemical shift (GIAO method) values of the title compound are calculated...
متن کاملTheoretical Investigation of Interaction between 5-Fluorouracil Anticancer Drug with Various Nitrosamine Compounds
We present detailed theoretical studies of the H-bonded complexes formed from interaction between 5-fluorouracil and various six-membered cyclic nitrosamine compounds. In this study, an investigation on intermolecular interactions in X-NU (X = CH2, SiH2,BH, AlH, NH, PH, O and S) complexes is carried out using density functional theory. The calculations are conducted on B3L...
متن کاملThe Influence of Cation-π Interactions on the Strength and Nature of Intramolecular O...H Hydrogen Bond in Orthohydroxy Benzaldehyde Compound
The influence of cation-π interactions on the strength and nature of intramolecular O...H hydrogen bond has been investigated by quantum chemical calculations in orthohydroxy benzaldehyde (HBA) compound. Ab initio calculations have been performed at MP2/6-311++G** level of theory. Vibrational frequencies and physical properties such as chemical potential and chemical hardness of these compounds...
متن کاملQuantum mechanical investigation of 4-hydroxy phenyl azobenzene adsorption on the boron nitride nanotubes
In this study, the adsorption of 4-hydroxy phenyl-azobenzene on the surface of (4, 0) zigzag open-end boron nitride nanotube (BNNT) has been investigated by quantum calculations. In order to find the preferred adsorption site, different positions and orientations were considered. The impacts of donor-acceptor electron delocalization on the structural and electronic properties and reactivity of ...
متن کاملElectronic Structure Investigation of Octahedral Complex and Nano ring by NBO Analysis: An EPR Study
To calculation non-bonded interaction of the [CoCl6]3- complex embedded in nano ring, we focus on the single wall boron-nitride B18N18 nano ring. Thus, the geometry of B18N18 nano ring has been optimized by B3LYP method with EPR-II (Electron paramagnetic resonance) basis set and geometry of the [CoCl6]3- complex has been optimized at B3LYP method with Aldrich’s VTZ basis set and Stuttgart RSC 1...
متن کامل