Islands of shape coexistence from single-particle spectra in covariant density functional theory

Using covariant density functional theory with the DDME2 and labeling single-particle energy orbitals by Nilsson quantum numbers, a search for particle-hole (p-h) excitations connected to appearance of shape coexistence is performed $Z=38$ 84. Islands are found near magic numbers $Z=82$ $Z=50$, restricted in regions around relevant neutron midshells $N=104$ $N=66$, respectively, accordance well-accepted p-h interpretation these regions, which we call neutron-induced coexistence, since neutrons act as elevators creating holes proton orbitals. Similar but smaller islands $N=90$ $N=60$, $Z=66$ $Z=39$, related across three-dimensional isotropic harmonic-oscillator $N=112$ $N=70$, correspond beginning participation opposite parity $1{i}_{13/2}$ $1{h}_{11/2}$, onset deformation. We this case proton-induced protons orbitals, thus offering possible microscopic mechanism regions. In region $N=40$, $Z=40$, an island located on both present.