Journal ArticleDOI
Natural Expansion of Exact Wavefunctions. II. The Hydrogen‐Molecule Ground State
Ernest R. Davidson,Leon L. Jones +1 more
TLDR
The Kolos and Roothaan wave function for H2 has been analyzed into natural orbitals and it was found that the first natural orbital is nearly the SCF function as mentioned in this paper.Abstract:
The Kolos and Roothaan wavefunction for H2 has been analyzed into natural orbitals. It was found that the first natural orbital is nearly the SCF function. The first four natural orbitals provide a good description of the molecule and give a total energy of —1.169884 hartrees. Beyond the first four terms, the natural expansion becomes more slowly convergent.read more
Citations
More filters
Journal ArticleDOI
Coherent X‐Ray Scattering for the Hydrogen Atom in the Hydrogen Molecule
TL;DR: In this paper, the x-ray form factors for a bonded hydrogen in the hydrogen molecule have been calculated for a spherical approximation to the bonded atom, and the corresponding complex scattering factors have also been calculated.
Journal ArticleDOI
Complete basis set correlation energies. I. The asymptotic convergence of pair natural orbital expansions
TL;DR: In this paper, an expression for the correlation energy of a multiconfiguration wave function is developed using perturbation theory, and three levels of extrapolation based on the asymptotic convergence of pair natural orbital expansions are examined.
Journal ArticleDOI
Extended Hartree—Fock Wavefunctions: Optimized Valence Configurations for H2 and Li2, Optimized Double Configurations for F2
G. Das,Arnold C. Wahl +1 more
TL;DR: In this paper, a configuration mixing method of the following nature is developed and illustrated for H2, Li2, and F2, which is capable of handling homonuclear diatomic molecules using as many as ten configurations.
Journal ArticleDOI
Direct Determination of Natural Orbitals and Natural Expansion Coefficients of Many‐Electron Wavefunctions. I. Natural Orbitals in the Geminal Product Approximation
TL;DR: In this paper, a generalized pair orbital function is defined in terms of its natural expansion and an iterative resolution procedure is proposed for the special case of a singlet state by minimizing the total electronic energy.
References
More filters
Journal ArticleDOI
Accurate Electronic Wave Functions for the H 2 Molecule
W. Kolos,Clemens C. J. Roothaan +1 more
Journal ArticleDOI
Natural Orbitals in the Quantum Theory of Two-Electron Systems
Per-Olov Löwdin,Harrison Shull +1 more
TL;DR: In this article, the wave functions for the singlet and triplet states of a two-electron system in a given nuclear framework are investigated as superpositions of configurations and are shown to be transformationally equivalent to quadratic forms having certain ranks and signatures.
Journal ArticleDOI
Many-electron theory of atoms and molecules. i. shells, electron pairs vs many-electron correlations
TL;DR: In this paper, a theory is developed to see what the physically important features of correlation in atoms and molecules are, based on this to obtain a quantitative scheme for N −electron systems as in He and H2.
Journal ArticleDOI
The dissociation energies of the H2, HD, and D2 molecules
G. Herzberg,A Monfils +1 more
TL;DR: The far ultraviolet absorption edges of H2, HD, and D2 have been studied under high resolution and the different limits corresponding to absorption from different lower state rotational levels have been observed as mentioned in this paper.
Related Papers (5)
Quantum Theory of Many-Particle Systems. I. Physical Interpretations by Means of Density Matrices, Natural Spin-Orbitals, and Convergence Problems in the Method of Configurational Interaction
Natural Orbitals in the Quantum Theory of Two-Electron Systems
Per-Olov Löwdin,Harrison Shull +1 more