  The present study focuses on investigating the shape evolution of
neutron-rich even-even Osmium (Os) transitional nuclei within the range of
neutron number N = 82 to N = 190. The investigation is conducted using
density-dependent meson-nucleon and point-coupling models within the framework
of the covariant density functional theory (CDFT). Additionally, the results
obtained from the CDFT calculations are compared with those obtained using the
relativistic mean-field model with a non-linear meson-nucleon interaction. The
potential energy curve for Os isotopes (ranging from $^{158}$Os to $^{260}$Os)
is analyzed in order to identify phase shape transitions, such as
oblate-spherical-prolate. Furthermore, ground state bulk properties are
calculated to gain insights into the structure of Os isotopes. The
self-consistent calculations reveal a clear shape transition in the even-even
Os isotopes, and overall, good agreement is observed among the different models
employed as well as with the available experimental data.
