<div dir="ltr"><div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:monospace,monospace;font-size:small;color:rgb(0,0,0)"><br clear="all"></div><div class="gmail_default"><div class="gmail_default"><font color="#000000" face="monospace, monospace">Dear QE users,</font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace">I recently calculated the band structure of the Tantalum Arsenide (TaAs) with SOC using the Projector Augmented Wave </font><span style="color:rgb(0,0,0);font-family:monospace,monospace">(PAW)</span><span style="color:rgb(0,0,0);font-family:monospace,monospace"> pseudopotential. I got a result which is not consistent with what exists in the literature. Actually, when we include the SOC a small gap should open up at the Fermi level. </span></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace">To perform that calculation, I added the following three line in my SCF input files </font></div><div class="gmail_default"><br></div><div class="gmail_default"><font color="#000000" face="monospace, monospace">    <b>lspinorb = .true.,</b></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><b>    noncolin = .true.,</b></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><b>    starting_magnetization = 0.0,</b></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><div class="gmail_default"><font color="#000000" face="monospace, monospace">as did in Quantum Espresso Example 7: </font><a href="https://github.com/maxhutch/quantum-espresso/blob/master/PW/examples/example07/run_example">https://github.com/maxhutch/quantum-espresso/blob/master/PW/examples/example07/run_example</a> and explained here: <a href="https://www.quantum-espresso.org/Doc/pw_user_guide/node10.html">https://www.quantum-espresso.org/Doc/pw_user_guide/node10.html</a></div></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><span style="color:rgb(0,0,0);font-family:monospace,monospace">I thought of changing the pseudopotential (PAW) that I used in order to see if I get a better result. </span></div><div class="gmail_default"><span style="color:rgb(0,0,0);font-family:monospace,monospace">So, I thought of using the ultrasoft pseudopotential (USPP) but I found this link </span><a href="https://www.researchgate.net/post/If_I_would_like_to_add_spin-orbit_coupling_in_band_structure_calculations_what_changes_should_I_do_in_the_input_file_in_Quantum_ESPRESSO" target="_blank">https://www.researchgate.net/post/If_I_would_like_to_add_spin-orbit_coupling_in_band_structure_calculations_what_changes_should_I_do_in_the_input_file_in_Quantum_ESPRESSO</a><span style="color:rgb(0,0,0);font-family:monospace,monospace"> where it is said that the option <b>lspinorb= .TRUE.</b> works only for PAW potentials and is not supported for ultrasoft pseudopotentials.</span></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><b>Are the ultrasoft pseudopotentials not supported for SOC calculation in QE?</b></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace">Below is the input file that I used to perform the SOC calculation</font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><br></font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace"><div class="gmail_default">&CONTROL</div><div class="gmail_default"><span style="white-space:pre">           </span> calculation = 'scf',</div><div class="gmail_default"><span style="white-space:pre">         </span>      prefix = 'TaAs',</div><div class="gmail_default">                restart_mode = 'from_scratch',</div><div class="gmail_default">                  pseudo_dir = './',</div><div class="gmail_default">                      outdir = './',<span style="white-space:pre">     </span></div><div class="gmail_default"><span style="white-space:pre">      </span>       etot_conv_thr = 1.0e-5,</div><div class="gmail_default"><span style="white-space:pre">            </span>  wf_collect = .true.</div><div class="gmail_default">                      </div><div class="gmail_default">/</div><div class="gmail_default">&SYSTEM</div><div class="gmail_default">                       ibrav = 7,</div><div class="gmail_default">                           A = 3.4348002616,</div><div class="gmail_default"><span style="white-space:pre">                        </span>   B = 3.4348002616,</div><div class="gmail_default"><span style="white-space:pre">                        </span>   C = 11.641,</div><div class="gmail_default"><span style="white-space:pre">              </span>       cosAB = 0,</div><div class="gmail_default"><span style="white-space:pre">         </span>       cosAC = 0,</div><div class="gmail_default"><span style="white-space:pre">         </span>       cosBC = 0,</div><div class="gmail_default">                         nat = 8,</div><div class="gmail_default">                        ntyp = 2,</div><div class="gmail_default">                     ecutwfc = 65,</div><div class="gmail_default">                     ecutrho = 400,</div><div class="gmail_default">         <span style="white-space:pre"> </span> occupations = 'smearing',</div><div class="gmail_default">                    smearing = 'M-P',</div><div class="gmail_default">                     degauss = 0.010,</div><div class="gmail_default"><span style="white-space:pre">               </span>    noncolin = .true.,</div><div class="gmail_default"><span style="white-space:pre">              </span>    lspinorb = .true.,</div><div class="gmail_default">   starting_magnetization(1) = 0.0</div><div class="gmail_default"><br></div><div class="gmail_default">/</div><div class="gmail_default">&ELECTRONS</div><div class="gmail_default"><span style="white-space:pre">     </span>            conv_thr = 1.0e-11,</div><div class="gmail_default"><span style="white-space:pre"> </span>         mixing_mode = 'plain',</div><div class="gmail_default">                 mixing_beta = 0.7,</div><div class="gmail_default">             diagonalization = 'cg'</div><div class="gmail_default">/</div><div class="gmail_default"> ATOMIC_SPECIES</div><div class="gmail_default">   Ta   180.94788  Ta.rel-pbe-spn-kjpaw_psl.0.2.UPF</div><div class="gmail_default">   As   74.9216    As.rel-pbe-n-kjpaw_psl.0.2.UPF</div><div class="gmail_default"> ATOMIC_POSITIONS {crystal}</div><div class="gmail_default">Ta      -0.124991858   0.064689851   0.147167066</div><div class="gmail_default">Ta       0.875311297   0.310797136   0.394149993</div><div class="gmail_default">Ta      -0.623651114   0.938399569   0.521894272</div><div class="gmail_default">Ta       0.374704885   0.186136223   0.769306698</div><div class="gmail_default">As       0.374135075  -0.312099362   0.271944874</div><div class="gmail_default">As       0.374998589   0.438122101   1.021399771</div><div class="gmail_default">As      -0.125251295   0.561961687   0.646512176</div><div class="gmail_default">As       0.874744421  -0.188007205  -0.104374866</div><div class="gmail_default"> K_POINTS {automatic}</div><div class="gmail_default">  09 09 09  1 1 1</div><div><br></div></font></div><div class="gmail_default"><br></div><div class="gmail_default"><font color="#000000" face="monospace, monospace">Thanks</font></div><div class="gmail_default"><font color="#000000" face="monospace, monospace">Pacome</font></div></div><div><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><font face="tahoma, sans-serif" color="#073763"><span><span><span><b><font color="#999999">_</font><font color="#666666">__</font></b><b style="font-size:12.8px"><font color="#666666">_____________<br></font></b></span></span></span></font><font face="georgia, serif" style="font-size:12.8px"><font color="#073763">Pacome NGUIMEYA</font></font><div style="font-size:12.8px"><font color="#073763" face="georgia, serif">Ph.D. Candidate</font></div><div style="font-size:12.8px"><font color="#073763" face="georgia, serif">Computational Condensed Matter Physics</font></div><div style="font-size:12.8px"><font color="#073763" face="georgia, serif">University of Cape Town (UCT), South Africa</font></div><div style="font-size:12.8px"><font face="georgia, serif"><span style="font-size:12.8px"></span></font></div><div style="font-size:12.8px"><b style="font-size:small"><i><span lang="EN-US" style="font-family:Cambria,serif;color:green">“Be Yourself; everyone else is already taken.”</span></i><i><span lang="EN-US" style="font-family:Cambria,serif;color:green"> </span></i></b></div><div style="font-size:12.8px"><b style="font-size:small"><i><span lang="EN-US" style="font-family:Cambria,serif;color:green">Oscar Wilde</span></i></b></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div>