For a metal complex with d electrons, the analysis usually starts with the free ion.

For species with more than one d electron, things are much more complicated.

The third orbital contains eight again, except that in the more correct Sommerfeld treatment (reproduced in modern quantum mechanics) there are extra "d" electrons.

In the d-block the atoms of the elements have between 1 and 10 d electrons.

Transition metal compounds are paramagnetic when they have one or more unpaired d electrons.

In octahedral complexes with between four and seven d electrons both high spin and low spin states are possible.

These properties are due to metallic bonding by delocalized d electrons, leading to cohesion which increases with the number of shared electrons.

Spin states when describing transition metal coordination complexes refers to the potential spin configurations of the metal center's d electrons.

Because Ru(acac) is low spin, there is one unpaired d electron, causing this compound to be paramagnetic.

Instead the modified d electron count method is used.