Quadrupole and monopole generalized oscillator strength for 2p-3p, 2p-4p transition of neon atomic in the velocity formulation

The quadrupole and monopole generalized oscillator strengths (GOS) as a function of momentum transfer are calculated for the 2p - 3p and 2p - 4p transitions of the neon atom using the analytical Hartree - Fock (HF) wavefunctions for the ground- state and the wavefunctions for the excited states which are obtained numerically from the modified HF Slater equation. Calculations are carried out by using the HF method and random phase approximation with exchange in the velocity formulation. The positions and the number of the extrema in the GOS have received particular attention in the evaluation. Our calculated monopole GOS of 2p - 3p transition in velocity form reveals one maximum located between the experimental and theoretical results of other authors. The disagreement between our first maximum of the quadrupole GOS 2p - 3p transition with the experimental and other theoretical ones is unimportant. The extrema of the monopole and quadrupole GOS of 2p - 4p transition are given in this paper. The results of velocity form study also show that the electron correlation effects are important around the maxima and are found to influence the positions of the extrema insignificantly.