  The electronic, elastic, structural, thermoelectric and optical parameters of
the Pb-based cubic perovskites $PbREO_3\; (RE=Ce,\; Gd,\; Nd)$ were calculated
using the WIEN2k Package. The mechanical optimization and structural
stabilities were evaluated. The found results are in full agreement with the
experimental ones. The obtained elastic results show that these perovskites
behave as stable ductile materials, and their higher $Y$ value gives them a
rigid structures. The $PbCeO_3$ presents n-type semiconductor while $PbREO_3\;
(RE= Gd,\; Nd)$ exhibit p-type semi-conductor with gap energies of $2.60\;eV$,
$1.02\;eV$ and $1.55\;eV$, respectively. The optical properties show that
$PbREO_3\; (RE=Ce,\; Gd,\; Nd)$ have significant absorption in the visible
light region with low reflectivity. The thermoelectric properties present a
desired electrical performance at room temperature for all materials. For these
generation of materials the effect of RE on Pb-based cubic perovskite oxides
can be exploited in manufacturing of thermoelectric, mechanic and
optoelectronic devices.
