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<p class="MsoNormal">Dear Quantum Espresso Users,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have been using the hp.x code to calculate the Hubbard-U corrections for correlated metallic systems in both their spin-polarised and paramagnetic states.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In several materials I have noticed that the Hubbard-U value determined for a material in its paramagnetic ground state is approximately twice that compared to when a spin-polarised ground state is assumed (with all other parameters kept
the same).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I was wondering whether anyone had any insight into how the accounting for spins in occupied Hubbard states works for the hp.x code and whether the paramagnetic implementation of hp.x perhaps counts all spins states twice resulting in this
larger value.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you in advance,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Theo Weinberger<o:p></o:p></p>
<p class="MsoNormal">PhD Student<o:p></o:p></p>
<p class="MsoNormal">University of Cambridge<o:p></o:p></p>
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