We study the role of the tensor term of the Skyrme effective interactions on the s
pin–orbit s
plittings in the
N=82 isotones and
Z=50 isoto
pes. The different role of the tri
plet-even and tri
plet-odd tensor forces is
pointed out by analyzing the s
pin–orbit s
plittings in these nuclei. The ex
perimental isos
pin de
pendence of these s
plittings cannot be described by Hartree–Fock calculations em
ploying the usual Skyrme
parametrizations, but is very well accounted for when the tensor interaction is introduced. The ca
pability of the Skyrme forces to re
produce binding energies and charge radii in heavy nuclei is not destroyed by the introduction of the tensor term. Finally, we also discuss the effect of the tensor force on the centroid of the Gamow–Teller states.