“…Together with experimental efforts, various theories have been applied to elucidate what kinds of shape are involved and how they evolve, including those employing Bohr's collective Hamiltonian [11,12], self-consistent triaxial mean-field models [13], shell-model-based approaches [14,15], beyond (relativistic) mean-field studies [12,16,17], constrained Hartree-Fock-Bogoliubov (plus local Random-Phase-Approximation) calculations [18,19], the Total Routhian Surface method [20], and self-consistent Nilsson-like calculation [21]. In general, many of the global features of these Kr isotopes, such as the coexistence of prolate and oblate shapes, their strong mixing at low angular momentum, the deformation of collective bands, the low-spin spectra and the systematics of excitation energies and transition strengths are reproduced.…”