  We describe the structural and electronic properties of graphene doped with
substitutional impurities of 4d and 5d transition metals. The binding energy
and distances for 4d and 5d metals in graphene show similar trends for the
later groups in the periodic table, which is also well-known characteristic of
3d elements. However, along earlier groups the 4d impurities in graphene show
very similar binding energies, distances and magnetic moments to 5d ones, which
can be related to the influence of the 4d and 5d lanthanide contraction.
Surprisingly, within the manganese group, the total magnetic moment of
3$\mu_{B}$ for manganese is reduced to 1$\mu_{B}$ for technetium and rhenium.
We find that with compared with 3d elements, the larger size of the 4d and 5d
elements causes a high degree hybridization with the neighbouring carbon atoms,
reducing spin splitting in the d levels. It seems that the magnetic adjustment
of graphene could be significantly different is 4d or 5d impurities are used
instead of 3d impurities.
