Criticality in the configuration-mixed interacting boson model: (2) – mixing

The case of – mixing in the interacting boson model is studied within its mean-field approximation. It is shown that the criticality conditions lead to two classes of solutions and that χ1 and χ2 need to have an opposite sign to allow for prolate–oblate shape coexistence. No evidence for a stable triaxial minimum is found. Phase diagrams for selected cases have been constructed.