Nilsson orbital assignments for rotational bands in ${}_{}{}^{99}{}_{}{}^{}\mathrm{Y}$ were identified in a previous paper, which showed that γ-ray relative intensities (both intraband M1+E2 and interband M1 or E1 γ transitions) depopulating all levels in the three lowest bands in ${}_{}{}^{99}{}_{}{}^{}\mathrm{Y}$ were well reproduced by a simple particle-rotor model. The present paper examines a recent proposal that the 536-keV band be reassigned as (3/2[431] (instead of (3/2[301] as previously proposed) and shows that this (3/2[431] proposal cannot be reconciled with observed γ-decay patterns from levels in the 536-keV band.

• Received 18 May 1987

DOI:https://doi.org/10.1103/PhysRevC.36.1204