12Be molecular states in a microscopic cluster model

The 12Be spectrum is investigated in the Generator Coordinate Method, using microscopic 6He+6He and α+8He wave functions. The model is consistent with recent experimental observations of molecular states, but predicts a strong mixing of both configurations, rather than a dominant 6He+6He structure. A negative-parity band is also found. Electromagnetic transition probabilities and partial widths of molecular states are calculated.