In the paper "Orbital effects in solids: basics, recent progress and opportunities" by Khomskii and Streltsov it is written for d1 electronic configuration, where the crystal field is octahedral, the ground state energy is j = 3/2 out of j = 1/2 and 3/2 however for d4 the lowest energy state is j = 0, out of J = 0, 1 ,2.

The Hunds Rule however states the opposite:

For less than half-filled sub-shells, the lowest J-level lies lowest, but for more than half-filled sub-shells it is the reverse, that is, the highest J-level lies lowest in energy.

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