The Structure of 9Be by a Molecular Model. II

Abstract

Motion of a valence neutron around two α-clusters is solved by the generator coordinate method with the effective nucleon-nucleon force which describes satisfactorily α+n and α+α systems at low energies. It is shown that the wave functions obtained in the present calculation have two-center-like distributions and are well represented in terms of simple molecular orbitals, especially, in the ground rotational band. As for the positive parity states, additional components to the LCAO approximation are needed for quantitative discussion on the structure of a 9Be nucleus. The motion is determined essentially by an effect of the Pauli principle between the valence neutron and a 8Be core. Experimental energy levels are reproduced with a right binding energy from the 8Be + n threshold. Charge form factors for electron scattering to positive parity states are also reproduced as well as an r.m.s.-radius and a quadrupole moment of the ground state and charge form factors to members of the ground rotational band.