A remark on the relation between Hartree–Fock orbital energies and the Hartree–Fock total energy in molecules

1977 ◽  
Vol 67 (10) ◽  
pp. 4771-4772 ◽  
Author(s):  
Tosinobu Anno ◽  
Yoshiko Sakai
Keyword(s):  
Total Energy ◽  
Hartree Fock ◽  
Orbital Energies

Relativistic Hartree–Fock–Roothaan wavefunctions for atoms

1985 ◽  
Vol 63 (7) ◽  
pp. 1550-1552 ◽  
Author(s):  
Takashi Kagawa ◽  
Gulzari Malli
Keyword(s):  
Numerical Integration ◽  
Integration Method ◽  
Basis Functions ◽  
Numerical Integration Method ◽  
Hartree Fock ◽  
Orbital Energies ◽  
Good Agreement

Relativistic Hartree–Fock–Roothaan (RHFR) wavefunctions have been calculated for a large number of atoms up to radon (Z = 86) under the point nucleus approximation using STO's as basis functions. The calculated total as well as orbital energies are in very good agreement with the corresponding results obtained by the numerical integration method.

Prediction of the photoelectron spectrum for XPY2 (X = H, F, Cl; Y = O, S) type of molecules by ab initio and DFT methods

2006 ◽  
Vol 84 (1) ◽  
pp. 5-9 ◽  
Author(s):  
Didier Bégué ◽  
Jean-marc Sotiropoulos ◽  
Claude Pouchan ◽  
Daisy Y Zhang
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Radical Cations ◽  
Dft Methods ◽  
Functional Theory ◽  
Hartree Fock ◽  
Orbital Energies ◽  
Koopmans Theorem ◽  
Vertical Ionization Potentials ◽  
Hybrid Density Functional

The present study reports the theoretical vertical ionization potentials (IPs) for all the valence electrons in six XPY2 molecules by utilizing the corrected orbital energies calculated with three theoretical methods, namely, the ab initio Hartree–Fock (HF), and both the pure and hybrid density functional theory (DFT) methods at, respectively, the BLYP/6-311+G* and B3lYP/6-311+G* levels of theory. Evaluation of the numerical corrections to the orbital energies was achieved by comparisons with the IP values obtained via explicit computation of the energy differences between the neutral molecules and the corresponding radical cations (the ΔSCF method) and shows values from –0.9 to –1.9 eV for the HF, and positive values from 2.9 to 3.9 eV and from 1.8 to 2.4 eV for the pure and hybrid DFT methods, respectively. In contrast to the orbital energies, the ΔSCF method is shown to give consistent values among the three methods, as well as reasonable agreement with the experimental IP values.Key words: ionization potential, phosphorane, Koopmans' theorem, Janak's theorem.

The quantum theory of lattice dynamics. Il

1969 ◽  
Vol 310 (1500) ◽  
pp. 89-99 ◽  
Keyword(s):  
Quantum Theory ◽  
Total Energy ◽  
Ground State ◽  
Lattice Dynamics ◽  
Equilibrium Configuration ◽  
Third Order ◽  
Hartree Fock

Expressions are derived for the expansion of the total energy of the electrons in their ground state in a crystal in powers of displacements of the nuclei from their equilibrium configuration. The expansion is taken up to third order on the basis of the coupled Hartree-Fock equations and thus one obtains expressions for the electronic contributions to the dynamical and anharmonic tensors.

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