Bohr model-based Helium.  If the orbital planes of the two electrons of Helium are perpendicular to each other, their total energy is consistent with the Helium ground state energy.
Please see <a rel="nofollow" class="external free" href="https://arxiv.org/abs/0903.2546">https://arxiv.org/abs/0903.2546</a> in detail.
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<span class="int-own-work" lang="en">Own work</span>