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<p class="MsoNormal" style="background:white"><span style="color:#282828"><o:p> </o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">Hello,<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">I am trying to calculate the magnetization of NdFeB which is a ferromagnetic material and a metal. This calculation has been done before using different methods than plane
waves and pseudopotentials. Moreover, the magnetization per formula unit has been experimentally measured. The previous calculations and experimental values agree and report a magnetization per formula unit of around 37 Bohr Magneton. The previous calculations
used the Generalized Gradient Approximation for the exchange correlation functional.<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">We first tried the calculation using the default number of bands and the input file is attached below:<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black"> <o:p></o:p></span></p>
<pre style="background:white;word-wrap:break-word;white-space:pre-wrap"><span style="color:black">&control<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> calculation='scf'<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> restart_mode='from_scratch',<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> wf_collect=.TRUE.,<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> prefix='NdFeB',<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> pseudo_dir = '/usr/local/espresso/espresso-5.0.3/pseudo/',<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> outdir = '/fs/lustre/osu7834/NdFeB/'<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">/<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">&system<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> ibrav=0, nat=68, ntyp=3,<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> nspin=2, starting_magnetization(1)=0.6, starting_magnetization(2)=0.6, starting_magnetization(3)=0.6,<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> ecutwfc = 260.0<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> occupations='smearing', smearing='mv', degauss=0.002<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">/<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">&electrons<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> conv_thr=1.0e-6<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> mixing_beta=0.02<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> mixing_mode = 'local-TF'<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">/<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">CELL_PARAMETERS {angstrom}<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">8.8 0.0 0.0<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">0.0 12.19 0.0<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">0.0 0.0 8.8<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">ATOMIC_SPECIES<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 144.24 Nd.pbe-mt_fhi.UPF<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 55.845 Fe.pbe-mt_fhi.UPF <o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">B 10.811 B.pbe-mt_fhi.UPF <o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">ATOMIC_POSITIONS {angstrom}<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">B 5.54400 0.00000 3.25600<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">B 3.25600 0.00000 5.54400<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">B 7.65600 6.09500 7.65600<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">B 1.14400 6.09500 1.14400<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.40000 0.00000 0.00000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.40000 6.09500 0.00000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.00000 6.09500 4.40000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.00000 0.00000 4.40000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.40000 1.37747 4.40000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.00000 7.47247 0.00000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.00000 4.71753 0.00000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.40000 10.81253 4.40000<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.85360 2.49895 0.85360<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 7.94640 2.49895 7.94640<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 5.25360 8.59395 3.54640<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 3.54640 8.59395 5.25360<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 5.25360 3.59605 3.54640<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 3.54640 3.59605 5.25360<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.85360 9.69105 0.85360<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 7.94640 9.69105 7.94640<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 2.79840 3.01093 2.79840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 6.00160 3.01093 6.00160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 7.19840 9.10593 1.60160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 1.60160 9.10593 7.19840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 7.19840 3.08407 1.60160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 1.60160 3.08407 7.19840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 2.79840 9.17907 2.79840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 6.00160 9.17907 6.00160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.99840 1.56032 1.97120<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 3.80160 1.56032 6.82880<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 6.37120 7.65532 8.20160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 2.42880 7.65532 0.59840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.59840 4.53468 2.42880<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 8.20160 4.53468 6.37120<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 1.97120 10.62968 4.99840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 6.82880 1.56032 3.80160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 3.80160 10.62968 6.82880<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.99840 10.62968 1.97120<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 2.42880 4.53468 0.59840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 6.37120 4.53468 8.20160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 8.20160 7.65532 6.37120<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.59840 7.65532 2.42880<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 6.82880 10.62968 3.80160<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 1.97120 1.56032 4.99840<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 3.15920 2.14544 0.34320<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 5.64080 2.14544 8.45680<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.74320 8.24044 1.24080<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.05680 8.24044 7.55920<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 7.55920 3.94956 4.05680<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 1.24080 3.94956 4.74320<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.34320 10.04456 3.15920<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 8.45680 2.14544 5.64080<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 5.64080 10.04456 8.45680<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 3.15920 10.04456 0.34320<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.05680 3.94956 7.55920<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 4.74320 3.94956 1.24080<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 1.24080 8.24044 4.74320<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 7.55920 8.24044 4.05680<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 8.45680 10.04456 5.64080<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Fe 0.34320 2.14544 3.15920<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 2.34080 0.00000 2.34080<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 6.45920 0.00000 6.45920<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 6.74080 6.09500 2.05920<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 2.05920 6.09500 6.74080<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 7.56800 0.00000 1.23200<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 1.23200 0.00000 7.56800<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 5.63200 6.09500 5.63200<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">Nd 3.16800 6.09500 3.16800<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"> <o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">K_POINTS {automatic}<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black">4 4 4 0 0 0<o:p></o:p></span></pre>
<pre style="background:white"><span style="color:black"><o:p> </o:p></span></pre>
<pre style="background:white"><span style="color:black"><o:p> </o:p></span></pre>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">This input file was prepared after checking convergence with respect to the energy cutoff and the number of points and did converge after 2 restart runs. Unfortunately,
we obtained a magnetization of 25 Bohr Magneton/f.u. (which is too small).<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">Furthermore, and after checking for convergence with respect to the number of bands (by adding more bands) we found that we end up with a magnetization of 50 Bohr Magneton/f.u.
(which is too big).<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">I also think that the degauss value used for smearing is small enough and can't be the problem.<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">Are there any recommendations for what other parameters I could examine to help me get the right answer?<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">Your help is greatly appreciated!<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Sincerely,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Michael Kurth<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">Graduate Student in Nuclear Engineering<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">Department of Mechanical and Aerospace Engineering<o:p></o:p></span></p>
<p style="background:white"><span style="font-family:"Calibri","sans-serif";color:black">The Ohio State University <o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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