A SIMPLE METHOD OF ACCOUNTING FOR CORRELATION-EFFECTS IN ELECTRON TRANSITIONS AND ITS APPLICATION IN FINDING OSCILLATOR-STRENGTHS AND THE SOLAR ABUNDANCE OF ZIRCONIUM

A simple method of accounting for correlation effects in complex atoms and ions, having several open electronic shells, is described. It is based on the use of the so-called transformed radial orbitals to descr ibe the admired electronic configurations in the framework of the supe rposition-of-configurations method. The method has been applied to cal culate the energy spectra and oscillator strengths of electric dipole transitions in neutral and singly ionized zirconium. On the basis of n ew values of oscillator strengths, the photospheric abundance of zirco nium is found to be A(Zr)=log(N-Zr/N-H)+12.00=2.60+/-0.06 and, being i n close agreement with the meteoritic abundance, illustrates the reaso nable accuracy of the proposed method.