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Dear Wannier-ists,</div>
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I am currently attempting to wannierise a set of isolated valence bands for a spin-polarised system. I have successfully obtained MLWFs for the spin-up channel - these have very low Re/Im ratios and interpolate the band structure very well - but I cannot replicate
this for the spin-down channel. For the spin-up channel, I used the SCDM method for initial projections, and ran wannier90 to reach a convergence threshold of 1.0e-10 on the spread functional. Applying the same procedure to the spin-down channel yields MLWFs
which are almost as well localised (the total spread is marginally higher) but the Re/Im ratio is very large, suggesting that I am getting stuck in a local minimum.</div>
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What I have tried so far:</div>
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<li style="list-style-type: "- ";"><span>SCDM + random noise during minimisation</span></li><li style="list-style-type: "- ";"><span>Starting from projections on appropriately-chosen atomic orbitals</span></li><li style="list-style-type: "- ";"><span>Starting from totally random projections</span></li></ul>
<div>In each case, I end up with more or less the same total spread and the same large Re/Im ratios.</div>
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<div>Perhaps my intuition is incorrect, but this is all the wrong way round in my head. The spin-up channel contains d-bands at similar energy to p-bands, and yet this wannierises very well. The spin-down channel contains only the p-bands (the d-bands are above
the Fermi level), and yet I cannot seem to escape the local minimum.</div>
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<div>Any advice as to how I could further troubleshoot this issue would be much appreciated (and forgive my ignorance if I am missing obvious steps - I am relatively new to the world of Wannier functions).</div>
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<div>Thanks,</div>
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<div>Patrick<br>
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<div class="BodyFragment"><b><font size="2"><span style="font-size:10pt"></span>Patrick J. Taylor</font></b></div>
<div class="BodyFragment"><font size="2">Doctoral Researcher</font></div>
<div class="BodyFragment"><font size="2">Morgan Group</font></div>
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<div class="BodyFragment"><font size="2">1S 1.15,</font></div>
<div class="BodyFragment"><font size="2">Department of Chemistry,</font></div>
<div class="BodyFragment"><font size="2">University of Bath,</font></div>
<div class="BodyFragment"><font size="2">BA2 7AY<br>
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