Hi all,<div><br></div><div>I have searched the list but I'm a bit confused with the posts, so I'll pose my questions here.</div><div><br></div><div>I am running LDA+U with and without spin-orbit coupling for a structure in a cell with the following cell parameters (Bohr):</div>
<div><br></div><div><div>P LATTICE,NONEQUIV.ATOMS: 14127_P4/mbm </div><div>MODE OF CALC=RELA </div><div> 10.353171 10.353171 43.972470 90.000000 90.000000 90.000000</div>
</div><div><br></div><div>and a cell sampling of 12x12x3, which gives 432 points in the BZ, 42 in the IBZ. My RKMAX is 8 - it was necessary to go to such high values to converge the spin moment of the system, as well as the energy down to 1 mRy. I followed the procedure stated in the manual: started with the LSDA calculation, then included spin-orbit coupling and now I am including the U gradually (well, at this point, just trying to...). I have to get to U=4 eV, so I'm growing it in steps of 1 eV. </div>
<div><br></div><div>Convergence was very good for the LSDA+U calculations without SOC, and they have finished, already (that is, I have already gotten to the 4 eV in U). However, I am having problems converging the scf, with the charge and energy distances (as obtained by grep convergence case.dayfile) oscillating, and never attaining convergence, which I set to ec=0.00001 and cc=0.0001 (the numbers are appended by the end of this message). More than 40 SCF steps have passed.</div>
<div><br></div><div>Usually, in pseudopotential calculations, one possible solution is to decrease the mixing weight of the charge densities for the following SCF step, and the other is to increase the smearing temperature. I would like to tweak with the mixing rather than increasing the temperature, if possible, because from my experience, increasing the temperature can sometimes lead to a non-magnetic state. However, I see from the mailing list that (at least in LAPW calculations), too small a mixing can lead to pseudo-convergence - which I don't understand what is. So, my questions are the following:</div>
<div><br></div><div>1) What is the best thing to do to make my calculation converge: increase the mixing, or to diminish it? Should I change the mixing for MSEC1, and if so, by which amount? Or, would it be good to change to PRATT, instead? I am quite lost with regards to that.</div>
<div>2) Would the application of SOC to the already converged LSDA+U calculation yield too different results from starting from a converged LSDA+SOC with later inclusion of U?</div><div>3) What is the pseudo-convergence mentioned in previous emails in the list?</div>
<div><br></div><div>Of course, I will gladly provide more information, if needed.</div><div><br></div><div>Best regards,</div><div><br></div><div>Marcos</div><div>Universidad de Cantabria, Spain</div><div><br></div><div>
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<div><br></div><div>Convergence of energy and charge distances:</div><div><br></div><div><div>:ENERGY convergence: 0 0.00001 .0002941150000000</div><div>:CHARGE convergence: 0 0.0001 .0088826</div><div>:ENERGY convergence: 0 0.00001 .0000916950000000</div>
<div>:CHARGE convergence: 0 0.0001 .0085946</div><div>:ENERGY convergence: 0 0.00001 .0000428400000000</div><div>:CHARGE convergence: 0 0.0001 .0112915</div><div>:ENERGY convergence: 0 0.00001 .0001772500000000</div>
<div>
:CHARGE convergence: 0 0.0001 .0113780</div><div>:ENERGY convergence: 0 0.00001 .0002456850000000</div><div>:CHARGE convergence: 0 0.0001 .0104415</div><div>:ENERGY convergence: 0 0.00001 .0001420300000000</div><div>
:CHARGE convergence: 0 0.0001 .0083852</div>
<div>:ENERGY convergence: 0 0.00001 .0000500150000000</div><div>:CHARGE convergence: 0 0.0001 .0084675</div><div>:ENERGY convergence: 0 0.00001 .0001809700000000</div><div>:CHARGE convergence: 0 0.0001 .0134776</div>
<div>
:ENERGY convergence: 0 0.00001 .0001993400000000</div><div>:CHARGE convergence: 0 0.0001 .0112308</div><div>:ENERGY convergence: 0 0.00001 .0002392700000000</div><div>:CHARGE convergence: 0 0.0001 .0104208</div><div>
:ENERGY convergence: 0 0.00001 .0002088150000000</div>
<div>:CHARGE convergence: 0 0.0001 .0069138</div><div>:ENERGY convergence: 0 0.00001 .0001630050000000</div><div>:CHARGE convergence: 0 0.0001 .0109876</div><div>:ENERGY convergence: 0 0.00001 .0002176700000000</div>
<div>
:CHARGE convergence: 0 0.0001 .0012609</div><div>:ENERGY convergence: 0 0.00001 .0001806300000000</div><div>:CHARGE convergence: 0 0.0001 .0042825</div><div>:ENERGY convergence: 0 0.00001 .0000720450000000</div><div>
:CHARGE convergence: 0 0.0001 .0045301</div>
<div>:ENERGY convergence: 0 0.00001 .0000129050000000</div><div>:CHARGE convergence: 0 0.0001 .0011304</div><div>:ENERGY convergence: 0 0.00001 .0002283150000000</div><div>:CHARGE convergence: 0 0.0001 .0047456</div>
<div>
:ENERGY convergence: 0 0.00001 .0003098100000000</div><div>:CHARGE convergence: 0 0.0001 .0100820</div><div>:ENERGY convergence: 0 0.00001 .0003708750000000</div><div>:CHARGE convergence: 0 0.0001 .0087276</div><div>
:ENERGY convergence: 0 0.00001 .0000788950000000</div>
<div>:CHARGE convergence: 0 0.0001 .0090876</div><div>:ENERGY convergence: 0 0.00001 .0000849050000000</div><div>:CHARGE convergence: 0 0.0001 .0093747</div><div>:ENERGY convergence: 0 0.00001 .0000842350000000</div>
<div>
:CHARGE convergence: 0 0.0001 .0079561</div><div>:ENERGY convergence: 0 0.00001 .0000553500000000</div><div>:CHARGE convergence: 0 0.0001 .0122027</div><div>:ENERGY convergence: 0 0.00001 .0000434050000000</div><div>
:CHARGE convergence: 0 0.0001 .0109352</div>
<div>:ENERGY convergence: 0 0.00001 .0000227750000000</div><div>:CHARGE convergence: 0 0.0001 .0122136</div><div>:ENERGY convergence: 0 0.00001 .0000194300000000</div><div>:CHARGE convergence: 0 0.0001 .0121261</div>
<div>
:ENERGY convergence: 0 0.00001 .0000292700000000</div><div>:CHARGE convergence: 0 0.0001 .0131197</div><div>:ENERGY convergence: 0 0.00001 .0000360650000000</div><div>:CHARGE convergence: 0 0.0001 .0110031</div><div>
:ENERGY convergence: 0 0.00001 .0000300950000000</div>
<div>:CHARGE convergence: 0 0.0001 .0115123</div><div>:ENERGY convergence: 0 0.00001 .0000323600000000</div><div>:CHARGE convergence: 0 0.0001 .0099887</div><div>:ENERGY convergence: 0 0.00001 .0000147550000000</div>
<div>
:CHARGE convergence: 0 0.0001 .0110331</div><div>:ENERGY convergence: 0 0.00001 .0001196200000000</div><div>:CHARGE convergence: 0 0.0001 .0005253</div></div><meta http-equiv="content-type" content="text/html; charset=utf-8"><meta http-equiv="content-type" content="text/html; charset=utf-8">