SYSTEMATIC TRENDS IN THE LINE STRENGTHS AND RADIAL MATRIX-ELEMENTS OFE1 TRANSITIONS IN THE BE ISOELECTRONIC SEQUENCE

Line strength S and radial matrix element a for the dipole allowed tra nsitions within n=2 complex of ions in the Be isoelectronic sequence h ave been fitted in the forms Z(2)S = A + B/(Z - C) and Z sigma = A' B'/(Z - C'). The constants A, B, C and A', B', C' have been calculated by employing a non-linear least square method. The relevant data for S and sigma have been taken from calculations which includes correlati on effects. It is shown that the fitted values of A and A' are in exce llent accord with their hydrogenic values (Z --> alpha) provided that we express the zeroth-order wavefunction of the ground state 1s(2)2s(2 1)S as a quantum-mechanical admixture of the Hartree-Fock (HF) state 1 s(2)2s(21)S and the near-degenerate state 1s(2)2p(21)S.