  The problem of orbital collapse of the $5g$ and $6f$ electrons in atoms of
superheavy elements (SHE) is considered. Previously, the presence of the
orbital collapse was established for the $4f$ and $5f$ elements of the periodic
table. Because of the large centrifugal term for the $f$ and $g$ electrons, the
effective radial potential has two wells, one narrow and deep and the other
wide but shallow. Depending on the external parameters, the electron can be
either localized in the outer well with low binding energy and large average
radius or in the inner one with higher energy and smaller radius. In this work,
we demonstrate the existence of the orbital collapse for the $5g$ electrons
when changing the total angular momentum $J$ of the atom. We also found that
for some SHE elements, two different solutions of the same Dirac-Fock equations
may coexist, with the $5g$ electron localized either in the inner or outer
well. In both cases, the radial wave functions are nodeless. The problem of the
dual-state coexistence is studied by the configuration-interaction method in
the Dirac-Fock-Sturm orbital basis as well.
