Treatment of intershell correlation effects in a b i n i t i o calculations by use of core polarization potentials. Method and application to alkali and alkaline earth atoms
- 1 April 1984
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 80 (7), 3297-3310
- https://doi.org/10.1063/1.447083
Abstract
In the present approach the high reliability of ab initio techniques is combined with the easily amenable phenomenological core polarization concept for an efficient treatment of intershell correlation effects in all‐electron SCF and valence CI calculations. By use of only a single adjustable atomic parameter, which is related to the radius of the core and determines the cutoff at short range, our effective core polarization potential (CPP) accounts quantitatively for dynamical intershell correlation as well as exclusion effects on the correlation energy of the core. The applications refer to alkali and alkaline earth atoms (Li to K and Be to Ca) and a detailed analysis is performed for core polarization effects on ionization energies, electron affinities, oscillator strengths, polarizabilities, van der Waals coefficients, the valence electron density, and spin densities. Very accurate results are obtained for well‐known energetic properties and spin densities at the nucleus. With respect to the other applications we consider our results as the most reliable to date with an estimated uncertainty of 1%–2%.Keywords
This publication has 88 references indexed in Scilit:
- Inclusion of core-valence correlation effects in pseudopotential calculations. II. K2and KH lowest Σ+potential curves from valence-correlated wavefunctionsJournal of Physics B: Atomic and Molecular Physics, 1983
- Bounds to atomic properties: Electric polarizabilities of lithium isoelectronic sequence ionsInternational Journal of Quantum Chemistry, 1982
- The polarised frozen-core approximation: Oscillator strengths for the boron isoelectronic sequenceJournal of Quantitative Spectroscopy and Radiative Transfer, 1982
- A Gaussian basis for Rydberg orbitalsThe Journal of Chemical Physics, 1981
- Finite perturbation calculation for the static dipole polarizabilities of the atoms Na through CaPhysical Review A, 1976
- Finite perturbation calculations for the static dipole polarizabilities of the first-row atomsPhysical Review A, 1976
- Theoretical Electron Affinities for Some of the Alkali and Alkaline-Earth ElementsPhysical Review B, 1968
- On theValues of the Alkali AtomsPhysical Review B, 1949
- The quantal calculation of the photo-ionization cross-section of atomic potassiumProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1947
- Über den Einfluß der Deformierbarkeit der Ionen auf optische und chemische Konstanten. IThe European Physical Journal A, 1924