<div dir="ltr">Meaning not too large. Large forces would lead to bad relaxation to unrealistic structure that cause convergence problems<div><br></div><div>Duy Le</div><div>(UCF)</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jul 10, 2020 at 1:13 PM Coralie Khabbaz <<a href="mailto:khabbaz.coralie@gmail.com">khabbaz.coralie@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hello Duy Le,<div><br></div><div>Thank you so much for your answer. What do you mean by reasonable forces? I have performed several scf calculations before and I get energy values that are consistent. </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 10 Jul 2020 at 13:08, Duy Le <<a href="mailto:ttduyle@gmail.com" target="_blank">ttduyle@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">It could be because of non-realistic structure as a result of relaxation. Please check the force in previously converged scf to see if they are reasonable. If not you may need to remake the starting structure so it has reasonable forces.<div><br></div><div>Duy Le</div><div>(UCF)</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jul 10, 2020 at 12:53 PM Coralie Khabbaz <<a href="mailto:khabbaz.coralie@gmail.com" target="_blank">khabbaz.coralie@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Also, when I perform scf calculation (and not relaxation), my energy value converges!!</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 10 Jul 2020 at 12:30, Coralie Khabbaz <<a href="mailto:khabbaz.coralie@gmail.com" target="_blank">khabbaz.coralie@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div dir="ltr">Hello,<div><br></div><div>I am performing a relaxation calculation on my Tungsten nitride (WN) slab with a methane molecule adsorbed on its surface. My first scf calculations always converges, but all the other scf calculations keep oscillating a little bit, like this:</div><div><br></div><div><div>iteration #107 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.2</div><div><br></div><div> negative rho (up, down): 1.877E+02 1.832E+02</div><div><br></div><div> total cpu time spent up to now is 6820.6 secs</div><div><br></div><div> total energy = <span style="background-color:rgb(255,255,0)">-22310.34633946 Ry</span></div><div> Harris-Foulkes estimate = -22286.51427887 Ry</div><div> estimated scf accuracy < 36291.44935321 Ry</div><div><br></div><div> total magnetization = 0.88 Bohr mag/cell</div><div> absolute magnetization = 13.09 Bohr mag/cell</div><div><br></div><div> iteration #108 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 2.0</div><div><br></div><div> negative rho (up, down): 1.828E+02 1.844E+02</div><div><br></div><div> total cpu time spent up to now is 6849.8 secs</div><div><br></div><div> total energy = <span style="background-color:rgb(255,255,0)">-22482.46538384</span> Ry</div><div> Harris-Foulkes estimate = -22312.40216721 Ry</div><div> estimated scf accuracy < 36350.61037433 Ry</div><div><br></div><div> total magnetization = 0.84 Bohr mag/cell</div><div> absolute magnetization = 11.93 Bohr mag/cell</div><div><br></div><div> iteration #109 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.0</div><div><br></div><div> negative rho (up, down): 1.848E+02 1.794E+02</div><div><br></div><div> total cpu time spent up to now is 6888.4 secs</div><div><br></div><div> total energy = -22531.89474337 Ry</div><div> Harris-Foulkes estimate = -22546.66368909 Ry</div><div> estimated scf accuracy < 34615.41965371 Ry</div><div><br></div><div> total magnetization = 0.49 Bohr mag/cell</div><div> absolute magnetization = 8.33 Bohr mag/cell</div><div><br></div><div> iteration #110 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.5</div><div><br></div><div> negative rho (up, down): 1.882E+02 1.776E+02</div><div><br></div><div> total cpu time spent up to now is 6947.2 secs</div><div><br></div><div> total energy = -22697.64012878 Ry</div><div> Harris-Foulkes estimate = -22561.26019900 Ry</div><div> estimated scf accuracy < 35110.57986884 Ry</div><div><br></div><div> total magnetization = 1.02 Bohr mag/cell</div><div> absolute magnetization = 8.80 Bohr mag/cell</div><div><br></div><div> iteration #111 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.0</div><div><br></div><div> negative rho (up, down): 1.953E+02 1.846E+02</div><div><br></div><div> total cpu time spent up to now is 6984.5 secs</div><div><br></div><div> total energy = -22595.85493501 Ry</div><div> Harris-Foulkes estimate = -22716.54469069 Ry</div><div> estimated scf accuracy < 35636.87841917 Ry</div><div><br></div><div> total magnetization = 1.33 Bohr mag/cell</div><div> absolute magnetization = 11.84 Bohr mag/cell</div><div><br></div><div> iteration #112 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.0</div><div><br></div><div> negative rho (up, down): 2.248E+02 1.996E+02</div><div><br></div><div> total cpu time spent up to now is 7023.3 secs</div><div><br></div><div> total energy = -22958.24642440 Ry</div><div> Harris-Foulkes estimate = -22626.00971729 Ry</div><div> estimated scf accuracy < 38324.66640261 Ry</div><div><br></div><div> total magnetization = 1.31 Bohr mag/cell</div><div> absolute magnetization = 10.12 Bohr mag/cell</div><div><br></div><div> iteration #113 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.0</div><div><br></div><div> negative rho (up, down): 2.614E+02 2.124E+02</div><div><br></div><div> total cpu time spent up to now is 7070.7 secs</div><div><br></div><div> total energy = -23388.04862201 Ry</div><div> Harris-Foulkes estimate = -23409.72136428 Ry</div><div> estimated scf accuracy < 40154.38739523 Ry</div><div><br></div><div> total magnetization = 1.90 Bohr mag/cell</div><div> absolute magnetization = 15.87 Bohr mag/cell</div><div><br></div><div> iteration #114 ecut= 50.39 Ry beta=0.10</div><div> Davidson diagonalization with overlap</div><div> ethr = 1.00E-02, avg # of iterations = 3.5</div><div><br></div><div> negative rho (up, down): 2.824E+02 2.176E+02</div><div><br></div><div> total cpu time spent up to now is 7120.5 secs</div><div><br></div><div> total energy = -23737.17074269 Ry</div><div> Harris-Foulkes estimate = -23665.30705552 Ry</div><div> estimated scf accuracy < 35266.44456712 Ry</div><div><br></div><div> total magnetization = 2.56 Bohr mag/cell</div><div> absolute magnetization = 16.20 Bohr mag/cell</div></div><div><br></div><div><b>How can I make my scf calculation converge?</b></div><div><br></div><div>This is my <b>input</b> file:</div><div><br></div><div><div>&CONTROL</div><div> calculation = "relax"</div><div> forc_conv_thr = 1.00000e-03</div><div> max_seconds = 4.32000e+05</div><div> nstep = 300</div><div> pseudo_dir = "/home/coralee/projects/def-jkopysci/coralee/.pseudopot"</div><div>/</div><div><br></div><div>&SYSTEM</div><div> a = 8.32716e+00</div><div> angle1(1) = 0.00000e+00</div><div> angle1(2) = 0.00000e+00</div><div> angle2(1) = 0.00000e+00</div><div> angle2(2) = 0.00000e+00</div><div> b = 8.98689e+00</div><div> c = 2.52767e+01</div><div> cosab = 6.12323e-17</div><div> cosac = 6.12323e-17</div><div> cosbc = -1.85547e-01</div><div> degauss = 2.00000e-02</div><div> ecutrho = 4.75221e+02</div><div> ecutwfc = 5.03902e+01</div><div> ibrav = 12</div><div> nat = 53</div><div> nbnd = 480</div><div> nspin = 2</div><div> ntyp = 4</div><div> occupations = "smearing"</div><div> smearing = "gaussian"</div><div> starting_magnetization(1) = 2.00000e-01</div><div> starting_magnetization(2) = 2.00000e-01</div><div>/</div><div><br></div><div>&ELECTRONS</div><div> conv_thr = 1.00000e-05</div><div> diagonalization = "david"</div><div> electron_maxstep = 500</div><div> mixing_beta = 1.00000e-01</div><div> mixing_mode = "local-TF"</div><div> startingpot = "atomic"</div><div> startingwfc = "atomic+random"</div><div>/</div><div><br></div><div>&IONS</div><div> ion_dynamics = "bfgs"</div><div>/</div><div><br></div><div>&CELL</div><div>/</div><div><br></div><div>K_POINTS {automatic}</div><div> 2 2 1 0 0 0</div><div><br></div><div>ATOMIC_SPECIES</div><div>N 14.00674 N.pbe-n-kjpaw_psl.1.0.0.UPF</div><div>W 183.84000 W.pbe-spn-kjpaw_psl.1.0.0.UPF</div><div>C 12.01070 C.pbe-n-kjpaw_psl.1.0.0.UPF</div><div>H 1.00794 H.pbe-kjpaw_psl.1.0.0.UPF</div><div><br></div><div>ATOMIC_POSITIONS {angstrom}</div><div>N 3.203704 2.747410 14.771098</div><div>N 7.372735 2.759212 14.776453</div><div>N 3.208642 -1.731177 14.774215</div><div>N 7.371486 -1.734287 14.777353</div><div>W 3.214859 4.922015 14.312292</div><div>W 7.369397 4.914334 14.580589</div><div>W 3.207301 0.425737 14.576255</div><div>W 7.371014 0.424829 14.576439</div><div>N 1.113188 5.239676 14.637084</div><div>N 5.300454 5.246400 14.637081</div><div>N 1.125960 0.744616 14.647342</div><div>N 5.289215 0.745329 14.647446</div><div>W 1.122438 3.033042 14.425674</div><div>W 5.295367 3.033769 14.426077</div><div>W 1.124035 -1.452510 14.426388</div><div>W 5.289229 -1.455341 14.427007</div><div>N 3.210511 5.196004 12.452975</div><div>N 7.370831 5.189844 12.478804</div><div>N 3.207641 0.696907 12.479359</div><div>N 7.371300 0.696480 12.479853</div><div>W 3.206497 3.070844 12.536437</div><div>W 7.370775 3.078954 12.541331</div><div>W 3.207829 -1.415777 12.539146</div><div>W 7.371280 -1.416331 12.539239</div><div>N 1.125925 3.569153 12.369437</div><div>N 5.289946 3.569319 12.367599</div><div>N 1.125855 -0.924614 12.368587</div><div>N 5.289457 -0.924540 12.368612</div><div>W 1.125854 5.677831 12.169785</div><div>W 5.290755 5.676885 12.165625</div><div>W 1.126115 1.184835 12.168057</div><div>W 5.289247 1.185090 12.168067</div><div>N 3.207882 3.506729 10.422372 0 0 0</div><div>N 7.371462 3.506729 10.422372 0 0 0</div><div>N 3.207882 -0.986715 10.422372 0 0 0</div><div>N 7.371462 -0.986715 10.422372 0 0 0</div><div>W 3.207882 5.716584 10.333236 0 0 0</div><div>W 7.371462 5.716584 10.333236 0 0 0</div><div>W 3.207882 1.223140 10.333236 0 0 0</div><div>W 7.371462 1.223140 10.333236 0 0 0</div><div>N 1.126093 6.199382 10.052766 0 0 0</div><div>N 5.289672 6.199382 10.052766 0 0 0</div><div>N 1.126093 1.705938 10.052766 0 0 0</div><div>N 5.289672 1.705938 10.052766 0 0 0</div><div>W 1.126093 3.871912 10.000000 0 0 0</div><div>W 5.289672 3.871912 10.000000 0 0 0</div><div>W 1.126093 -0.621532 10.000000 0 0 0</div><div>W 5.289672 -0.621532 10.000000 0 0 0</div><div>C 3.206835 4.918476 16.276735 0 0 0</div><div>H 2.573835 4.285476 16.909735 0 0 0</div><div>H 3.839835 4.285476 15.643735 0 0 0</div><div>H 2.573835 5.551476 15.643735 0 0 0</div><div>H 3.839835 5.551476 16.909735 0 0 0</div><div><br></div><div><br></div></div><div><br></div></div></div></div>
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