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Hello,</div>
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I have a question about slabs. </div>
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I am using QE 7.4.1 (developer edition) for a slab along the z-axis. The bulk unit cell c-vector is (0,0,4.17) Å. </div>
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The system has a noncolinear spin configuration. </div>
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When I add a 5Å vacuum the calculation converges without any negative rho. </div>
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However, as I increase the vacuum thickness the calculation still converges but negative rho develops. </div>
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I thought that having more vacuum is better, but I am seeing the opposite, e.g for vacuum=12Å </div>
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I have: </div>
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negative rho (up, down): 1.218E-05 2.046E-02</div>
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at the end of the calculation.</div>
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Also, I have<b> lower </b>energy for vacuum=5Å than for vacuum=10,12,14,16,18,20 Å</div>
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Many Thanks,</div>
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<div dir="ltr"><span style="font-family: Aptos, sans-serif; font-size: 14.666667px; color: rgb(33, 33, 33);">Marios Georgiou</span><span style="font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span><span style="font-family: Aptos, sans-serif; font-size: 14.666667px; color: rgb(33, 33, 33);">School of Physics and Astronomy</span><span style="font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span><span style="font-family: Aptos, sans-serif; font-size: 14.666667px; color: rgb(33, 33, 33);">University of Leeds</span></div>
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