NEGATIVE-PARITY INVERSION DOUBLET ALPHA-CLUSTER BAND IN O-18

The alpha-cluster structure of the O-18 nucleus is investigated by stu dying the properties of a global optical model potential which describ es C-14(alpha,alpha) elastic scattering at 28, 40, and 54 MeV on the w hole angular range. This calculation does not support the existence of the negative-parity molecular dipole states which have been proposed to coexist with the positive-parity-four-particle-two-hole (4p-2h) def ormed band built on the J(pi) = 0+, E(x) = 3.63 MeV state. It suggests that the broad J(pi) = 1- state recently seen around E(x) = 9 MeV in the, beta-delayed alpha-particle spectrum from N-18 is the bandhead of the negative-parity inversion-doublet partner band of the 4p-2h band.