SYSTEMATIC TRENDS IN THE RADIAL MATRIX-ELEMENTS OF E1 TRANSITIONS IN LI, F, NA AND CU ISOELECTRONIC-SEQUENCES

Scaled radial matrix elements Z sigma for dipole allowed transitions i n Li, F, Na and Cu isoelectronic sequences have been fitted in the for m Z sigma = A + B/(Z - C) + D(Z - Ze)(2). The constants A, B, C, D are determined using a non-linear least square fit method; Z is the nucle ar charge of a particular ion and Ze is the number of electrons in the core. It has been shown that the fitted value A for various transitio ns studied is in good agreement with the non-relativistic ab-initio va lue A(0) of Z sigma in the limit Z --> infinity. The last term of the above expansion accounts for the relativistic effects for heavier ions which are significant for Z > 26. The coefficient D is proportional t o alpha(2) where alpha is a fine structure constant and is a measure o f relativistic contribution to allowed dipole radial matrix elements.