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Article
Energies of Atoms and Ions Calculated by the Hartree–Fock Method
Energies of atoms from hydrogen to calcium and all their ions up to the one-electron atom inclusively that were calculated in the algebraic approximation of the Hartree–Fock method were compared with the exper...
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Article
Calculation of the ground state energy of neutral atoms (Z ≤ 54) by the algebraic variant of the Hartree-Fock method
High-precision calculations of the ground-state energy of atoms He through Xe are performed in the algebraic approximation of the Hartree-Fock method. The orbital exponents of Slater-type basis functions are o...
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Article
Calculation of open p-shell atoms in the algebraic approach of the Hartree–Fock method
Highly precise calculations of analytical Hartree–Fock orbitals and energies have been performed within the limits of the Roothaan–Hartree–Fock atomic theory (Roothaan–Bagus method) for all open p-shell atoms ...
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Article
Computation of vector coupling coefficients for atoms with one and two open shells in the Hartree–Fock approximation
A new way to introduce and calculate vector coupling coefficients (VCCs) is proposed for computations in a Hartree–Fock approximation of atoms with one and two open shells. In the case of atoms with one open s...
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Article
Hartree–Fock self-consistent field method for atoms with two open shells of identical symmetry
A generalization of the Roothaan–Bagus method (Roothaan–Hartree–Fock atomic theory) on atoms with open shells of identical symmetry is given. Using orbital exponents of Slater-type atomic orbitals optimized wi...
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Article
Calculation of ground and excited states for atoms with an open f-shell in the Hartree-Fock-Roothaan approximation
Application of the Roothaan-Bagus method (Hartree-Fock atomic theory) for atoms with one open fn-shell is considered. Energy values for lanthanide atoms in the ground and excited states are calculated by minimiza...
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Article
Calculation of optical polarizability of atoms with two open shells in the Hartree-Fock approximation
Time-dependent Hartree-Fock equations (the Huzinaga method) in terms of density functionals have been obtained for a multielectronic system with two open shells of different symmetry species subjected to a tim...
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Article
Calculation of the dipole hyperpolarizability of atoms with closed and open shells by the Hartree-Fock-Roothaan method
The Hartree-Fock-Roothaan method is extended to the calculation of the hyperpolarizability of atoms. The static polarizability and hyperpolarizability of some atoms with closed and open shells are calculated u...
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Article
Stationary perturbation theory for atoms with two open shells in the Hartree-Fock approximation
Within the Hartree-Fock method, we have obtained equations of stationary “coupled” perturbation theory for multielectron systems with two open shells of different symmetry types (Huzinaga method) in the orbita...
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Article
Hartree-fock equations for atoms with two open shells
We have formulated the Hartree-Fock equations for multielectron systems with two open shells (the Huzinaga method) in terms of the density matrix in the LCAO approximation. In order to solve the Hartree-Fock e...
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Article
Calculations of the Energies of the Excited States of Open-Shell Atoms in the Hartree-Fock Approximation
In the framework of the Roothaan-Hartree-Fock atomic theory, the solution of a many-electron problem is considered on the basis of the methods of minimizing a function of many variables. To implement this appr...
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Article
Application of minimization methods in calculating atoms with several open shells
Basing on minimization methods, earlier suggested algorithms for the solution of a many-electron problem in Hartree-Fock-Roothaan approximation for systems with close and open shells extend over Roothaan-Hartr...
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Article
Calculation of the dynamic polarizability of open-shell atoms
The application of the authors’ nonstationary theory of perturbations in the Hartree-Fock approximation to calculation of the dynamic polarizability of open-shell atoms as an explicit function of the incident ...
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Article
Nonstationary Theory of Perturbations for Open-Shell Atoms in the Hartree–Fock Approximation
For a multielectron open-shell system exposed to an external time-dependent perturbation, the Hartree–Fock nonstationary equations are obtained in terms of density operators. Using them as a basis, equations o...
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Article
Calculation of optical characteristics of atoms with a closed shell by the Hartree-Fock-Roothaan method
The transition frequencies, oscillator strengths, and Cauchy moments of the dipole dynamic polarizability are calculated for the Ar, Ca, Sr, and Xe atoms and their isoelectronic sequences.
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Article
Linear Approximation of Basis Set Orbital Exponents for Isoelectronic Series of Atoms
The orbital exponents of Slater type atomic orbitals (AOs) in isoelectronic series of atoms may be approximated by the linear dependence on the nuclear charge using a technique developed for optimization of AO...
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Article
The Hartree–Fock Approximation Calculation of Electric Polarizability of Atoms with an Open Shell
Within the framework of the restricted Hartree–Fock method, equations of stationary “coupled” perturbation theory have been obtained for atomic-molecular systems with an open shell in orbital representation. C...
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Article
Hartree–Fock High-Precision Analytical Functions of Open-Shell Atoms
The algorithm of high-precision optimization of basis functions suggested previously for calculating the analytical Hartree–Fock orbitals of closed-shell atoms is generalized to open-shell systems described by...
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Article
Method of configuration interaction in calculations of the spectral characteristics of atoms and molecules
For He, Be, Ne, and Mg atoms and their isoelectronic series, calculations of the dipole dynamic polarizability, energies, and strengths of the oscillators of the lowest electronic transitions are made within t...
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Article
Hartree-Fock-Roothaan calculations of dipolar polarizabilities for closed-shell atoms
Methods are suggested for optimization of Slater type atomic orbitals in polarizability calculations of closed-shell atoms using “bound” perturbation theory (algebraic version of the Hartree-Fock method). The ...
