<span class="Apple-style-span" style="font-family: arial, sans-serif; font-size: 12.5px; border-collapse: collapse; "><div><div>In 4.2.1 manual, it is said that:<i>If .zue=<a href="http://true.is/" target="_blank" style="color: rgb(0, 137, 170); ">true.is</a> an alternative algorithm, different from the default one (if trans .and. epsil ) The results should be the same within numerical noise.</i></div>
</div><div><br></div><div><b>However, I get wrong "effective charges" in zue=true in AFM insulator CaMnO3 with </b><span class="Apple-style-span" style="font-size: 12.5px; "><b><span class="Apple-style-span" style="font-size: 10.4167px; ">4.2.1</span></b></span></div>
<div><b></b><span style="font-family: arial, sans-serif; font-size: 12.5px; border-collapse: collapse; "><b>These two Mn atoms are the same except antiparallel spin.</b></span></div><div><b>In "epsil+trans", effective charges of Mn1=7.79, Mn2=7.78;</b></div>
<div><b>In "zue" , effective charges of Mn1=3.1, Mn2=51.2;</b></div><div><br></div><div>I will describe my calculation procedure using <b>4.2.1</b> in short.</div><div>1: I do scf calculation in <a href="http://scf.in/" target="_blank" style="color: rgb(0, 137, 170); ">scf.in</a></div>
<div><div><i>restart_mode = 'from_scratch'</i></div></div><div><i>occupations = 'smearing'</i></div><div><div><i>smearing = 'gauss'</i></div><div><i>degauss = 0.002</i></div><div><i>starting_magnetization(1) = 1</i></div>
<div><i>starting_magnetization(2) = -1</i></div><div><i>starting_magnetization(3) = 0</i></div><div><i>starting_magnetization(4) = 0</i></div></div><div><br></div><div>2: I do a scf calculation in <a href="http://scf.in/" target="_blank" style="color: rgb(0, 137, 170); ">scf.in</a></div>
<div><i>restart_mode = 'restart'</i></div><div><div><i>occupations = 'fixed'</i></div><div><i>nspin = 2</i></div><div><i>tot_magnetization = 0</i></div></div><div>
<div><br></div><div>3: I do ph calculation with </div></div><div><div><i><span style="font-style: normal; "><div><div><i>zue = .TRUE. !the same with epsil and trans = TRUE</i></div></div><div>(In this condition, effective charges of Mn1=3.1, <b> Mn2=51.2</b>;)</div>
<div><i><span style="font-style: normal; ">or with:</span></i></div><div><i>epsil = .TRUE. , </i><i>trans = .TRUE. </i></div></span></i></div><div>(In this condition <i>, </i>effective charges of Mn1=7.79, Mn2=7.78;)</div>
<div><div><div><br></div><div>(The reason is why I restart scf is below: </div><div>"starting_magnetization" must be used with "smearing". However, "smearing" will give a metal result. Effective charges can not be calculated for metal. But, CaMnO3 is really a insulator AFM.</div>
<div>"occupations=fixed" can get a insulator result. However it must used with "tot_magnetization". If I use "tot_magnetization=0", I will get a PM no AFM state.</div><div>In the end, I use "smearing"+"starting_magnetization" to get a AFM metal. Then I use "fixed"+"tot_magnetization" to get a AFM insulator.</div>
<div><b>Is there any other good method to get a AFM insulator?</b>)</div></div></div></div><div><br></div><div><br></div><div>The following my script for "<i><span style="font-style: normal; "><i>zue= .TRUE</i></span> </i>"</div>
<div>And I have attached output file of "<i><span style="font-style: normal; "><i>zue= .TRUE</i></span> </i>" in accessary. Thanks:)</div><div><div><br></div><div>#*********************************************</div>
<div># scf-antimag-smearing</div><div>cat><a href="http://scf.in/" target="_blank" style="color: rgb(0, 137, 170); ">scf.in</a><<EOF</div><div>for vc-relax</div><div>&CONTROL</div><div>calculation = 'scf'</div>
<div>title = 'G-10-scf'</div><div>verbosity = 'high'</div><div>restart_mode = 'from_scratch'</div><div>wf_collect = .FALSE.</div><div>tstress = .TRUE.</div><div>tprnfor = .TRUE.</div>
<div>prefix = 'G-10-scf'</div><div>etot_conv_thr = 1.0e-4</div><div>forc_conv_thr = 1.0e-3</div><div>disk_io = 'low'</div><div>pseudo_dir = './'</div><div>/</div><div><br></div><div>
&SYSTEM</div><div>ibrav = 2</div><div>celldm = 14.20419765</div><div>nat = 10</div><div>ntyp = 4</div><div>nbnd = 50</div><div>ecutwfc = 70</div><div>ecutrho = 560</div>
<div>nosym = .FALSE.</div><div>!nosym_evc = .TRUE.</div><div>!noinv = .TRUE.</div><div>occupations = 'smearing'</div><div>smearing = 'gauss'</div><div>degauss = 0.002</div>
<div>starting_magnetization(1) = 1</div><div>starting_magnetization(2) = -1</div><div>starting_magnetization(3) = 0</div><div>starting_magnetization(4) = 0</div><div>!occupations = 'fixed'</div><div>
nspin = 2</div><div>!tot_magnetization = 0</div><div>/</div><div><br></div><div>&ELECTRONS</div><div>electron_maxstep = 100</div><div>conv_thr = 1.0e-7</div><div>mixing_mode = 'plain'</div>
<div>mixing_beta = 0.7</div><div>mixing_ndim = 8</div><div>diagonalization = 'david'</div><div>diago_david_ndim = 4</div><div>/</div><div><br></div><div>ATOMIC_SPECIES</div><div> Mn1 55 Mn.pbe-sp-van.UPF</div>
<div> Mn2 55 Mn.pbe-sp-van.UPF</div><div> Ca 40 Ca.pbe-nsp-van.UPF</div><div> O 16 O.pbe-rrkjus.UPF</div><div><br></div><div>ATOMIC_POSITIONS {crystal}</div><div> Mn1 0.00 0.00 0.00</div><div> Mn2 0.50 0.50 0.50</div>
<div> Ca 0.25 0.25 0.25</div><div> Ca 0.75 0.75 0.75</div><div> O 0.75 0.25 0.75</div><div> O 0.25 0.75 0.25</div><div> O 0.75 0.75 0.25</div><div> O 0.25 0.25 0.75</div><div>
O 0.25 0.75 0.75</div><div> O 0.75 0.25 0.25</div><div> </div><div><br></div><div>K_POINTS {automatic}</div><div>6 6 6 0 0 0</div><div>EOF</div><div>./dopw <<a href="http://scf.in/" target="_blank" style="color: rgb(0, 137, 170); ">scf.in</a> >G-scf-10-smearing.out</div>
<div><br></div><div># scf-antimag-insulator</div><div>cat><a href="http://scf.in/" target="_blank" style="color: rgb(0, 137, 170); ">scf.in</a><<EOF</div><div>for vc-relax</div><div>&CONTROL</div><div>calculation = 'scf'</div>
<div>title = 'G-10-scf'</div><div>verbosity = 'high'</div><div>restart_mode = 'restart'</div><div>wf_collect = .FALSE.</div><div>tstress = .TRUE.</div><div>tprnfor = .TRUE.</div>
<div>prefix = 'G-10-scf'</div><div>etot_conv_thr = 1.0e-4</div><div>forc_conv_thr = 1.0e-3</div><div>disk_io = 'low'</div><div>pseudo_dir = './'</div><div>/</div><div><br></div><div>
&SYSTEM</div><div>ibrav = 2</div><div>celldm = ${lattic_parameter} !bohr</div><div>nat = 10</div><div>ntyp = 4</div><div>nbnd = 50</div><div>ecutwfc = 70</div><div>ecutrho = 560</div>
<div>nosym = .FALSE.</div><div>!nosym_evc = .TRUE.</div><div>!noinv = .TRUE.</div><div>!occupations = 'smearing'</div><div>!smearing = 'gauss'</div><div>!degauss = 0.002</div>
<div>!starting_magnetization(1) = 1</div><div>!starting_magnetization(2) = -1</div><div>!starting_magnetization(3) = 0</div><div>!starting_magnetization(4) = 0</div><div>occupations = 'fixed'</div><div>
nspin = 2</div><div>tot_magnetization = 0</div><div>/</div><div><br></div><div>&ELECTRONS</div><div>electron_maxstep = 100</div><div>conv_thr = 1.0e-7</div><div>mixing_mode = 'plain'</div>
<div>mixing_beta = 0.7</div><div>mixing_ndim = 8</div><div>diagonalization = 'david'</div><div>diago_david_ndim = 4</div><div>/</div><div><br></div><div>ATOMIC_SPECIES</div><div> Mn1 55 Mn.pbe-sp-van.UPF</div>
<div> Mn2 55 Mn.pbe-sp-van.UPF</div><div> Ca 40 Ca.pbe-nsp-van.UPF</div><div> O 16 O.pbe-rrkjus.UPF</div><div><br></div><div>ATOMIC_POSITIONS {crystal}</div><div> Mn1 0.00 0.00 0.00</div><div> Mn2 0.50 0.50 0.50</div>
<div> Ca 0.25 0.25 0.25</div><div> Ca 0.75 0.75 0.75</div><div> O 0.75 0.25 0.75</div><div> O 0.25 0.75 0.25</div><div> O 0.75 0.75 0.25</div><div> O 0.25 0.25 0.75</div><div>
O 0.25 0.75 0.75</div><div> O 0.75 0.25 0.25</div><div> </div><div><br></div><div>K_POINTS {automatic}</div><div>6 6 6 0 0 0</div><div>EOF</div><div>./dopw <<a href="http://scf.in/" target="_blank" style="color: rgb(0, 137, 170); ">scf.in</a> >G-scf-10-insulator.out</div>
<div><br></div><div>#for phonon-antimag</div><div>cat><a href="http://ph.in/" target="_blank" style="color: rgb(0, 137, 170); ">ph.in</a> <<EOF</div><div>for phonon</div><div>&INPUTPH</div><div>amass(1) = 55</div>
<div>amass(2) = 55</div><div>amass(3) = 40</div><div>amass(4) = 16</div><div>outdir = "./"</div><div>prefix = 'G-10-scf' !must be the same with scf</div><div>ldisp = .FALSE.</div>
<div>niter_ph = 100</div><div>tr2_ph = 1.0e-12</div><div>alpha_mix(1)= 0.7</div><div>nmix_ph = 4</div><div>iverbosity = 1</div><div>fildyn = 'matdyn'</div><div>!epsil = .TRUE. !Do not set epsil to .true. for metallic system or q/=0</div>
<div>!trans = .TRUE. !if trans .and. epsil effective charges are calculated</div><div>zue = .TRUE. !the same with epsil and trans = TRUE</div><div>/</div><div>0.0 0.0 0.0</div><div>EOF</div><div><br></div><div>
./doph <<a href="http://ph.in/" target="_blank" style="color: rgb(0, 137, 170); ">ph.in</a> >G-ph-10.out</div><div>done</div></div><div>#*********************************************</div></span><br>-- <br>____________________________________<br>
Hui Wang<br>School of physics, Fudan University, Shanghai, China<br>