HARTREE-FOCK AND CORRELATION ENERGIES FOR 1s2s $sup 3$S AND $sup 1$S STATES OF HELIUM-LIKE IONS
The energies of the 1s2s /sup 3/S and /sup 1/S excited states of an atom of nuclear charge Z are calculated in the form of a series in ascending powers of l/Z. The first four terms in the series for these non-relativistic, but otherwise exact, energies are obtained numerically. The corresponding zeroth- order and first-order wave functions are calculatedthe former exactly, and the latter by a variational method-using up to twelve variable parameters. The energies of these states are also calculated within the Hartree--Fock scheme. A misunderstanding in the Hartree--Fock equations for the excited singlet state is corrected, and the zeroth-order and first-order wave functions are calculated exactly. Formulae are obtained from which, by numerical integration, these Hartree--Fock energies may be computed in a power series similar to that for the exact energy. Electron correlation is very small for the triplet, but larger for the singlet. Both values, however, are much less than those for the 1s/sup 2/ ground state. (auth)
- Research Organization:
- Oxford Univ., Eng.
- NSA Number:
- NSA-16-026004
- OSTI ID:
- 4800759
- Journal Information:
- Proc. Phys. Soc. (London), Journal Name: Proc. Phys. Soc. (London) Vol. Vol: 80
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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