The Structure of 9Be Nucleus by a Molecular Model. I

Abstract

The nucleus 9Be is investigated by an extended molecular-orbital model and by the generator coordinate method in the simple LCAO approximation. The Hartree-Fock calculations show that α-cluster structures are stable in intrinsic states and the degree of clustering depends crucially on motions of the valence neutron. The generator coordinate calculations give good descriptions of the energy level structures of normal and non-normal parity states in terms of rotational bands. Energy spectra of 9B are given as well. A Kπ=1/2- band is also predicted. The ground state properties, that is, r.m.s.-radius, Q-moment and µ-moment are reproduced as quite well as electric transitions and charge form factors for the members of the ground rotational band. It is concluded that the molecular model admirably succeeds in systematic explanation of the low energy properties of 9Be. Comparisons are made with the simple shell model and the projected Hartree-Fock calculation by Bouten et al.