  The evolution and coexistence of the nuclear shapes as well as the
corresponding low-lying collective states and electromagnetic transition rates
are investigated along the Krypton isotopic chain within the framework of the
interacting boson model (IBM). The IBM Hamiltonian is determined through
mean-field calculations based on the several parametrizations of the Gogny
energy density functional and the relativistic mean-field Lagrangian. The
mean-field energy surfaces, as functions of the axial $\beta$ and triaxial
$\gamma$ quadrupole deformations, are mapped onto the expectation value of the
interacting-boson Hamiltonian that explicitly includes the particle-hole
excitations. The resulting boson Hamiltonian is then used to compute low-energy
excitation spectra as well as E2 and E0 transition probabilities for
$^{70-100}$Kr. Our results point to a number of examples of the prolate-oblate
shape transitions and coexistence both on the neutron-deficient and
neutron-rich sides. A reasonable agreement with the available experimental data
is obtained for the considered nuclear properties.
