<div>Dear Prof. Paolo Giannozzi,</div><div><br></div><div>The two computers have the exact same OS (ubuntu), compilers (ifort), libraries, and parallel environments installed. It really strange why different results produced by the same inputs. Can anyone help me?</div><div><br></div><div>Best<br></div><div><br></div><div><div style="color:#909090;font-family:Arial Narrow;font-size:12px">------------------</div><div style="font-size:14px;font-family:Verdana;color:#000;"><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Dr. Jibiao Li, </b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Department of Material Science and Engineering</b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Yangtze Normal University</b></font></i></div><div><i><font face="Times New Roman"><font size="2"><font color="#0000ff"><b><span style="text-align: left; text-transform: none; line-height: 21px; text-indent: 0px; letter-spacing: normal; font-variant: normal; text-decoration: none; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; float: none; -webkit-text-stroke-width: 0px; background-color: transparent;">Juxian Dadao 16#,</span> Fuling, Chongqing, China</b></font></font></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Email: jibiaoli@yznu.edu.cn, jibiaoli@foxmail.com, jibiao.li@hotmail.com</b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Homepage: https://www.researchgate.net/profile/Jibiao_Li</b></font></i></div>
</div></div><div> </div><div><div><br></div><div><br></div><div style="font-size: 12px;font-family: Arial Narrow;padding:2px 0 2px 0;">------------------ Original ------------------</div><div style="font-size: 12px;background:#efefef;padding:8px;"><div><b>From:</b> "p.giannozzi"<p.giannozzi@gmail.com>;</div><div><b>Date:</b> Wed, Oct 9, 2019 09:42 PM</div><div><b>To:</b> "Quantum ESPRESSO users Forum"<users@lists.quantum-espresso.org>;<wbr></div><div></div><div><b>Subject:</b> Re: [QE-users] Computer dependent phonon frequencies</div></div><div><br></div><div dir="ltr"><div>Hard to say with no knowledge (or even with the knowledge) of which computers, compilers, libraries, parallel execution, ... produce strange results.<br></div><div><br></div><div>Paolo</div></div><br><div class="gmail_quote"><div class="gmail_attr" dir="ltr">On Wed, Oct 9, 2019 at 2:19 PM Jibiao Li <<a href="mailto:jibiaoli@foxmail.com">jibiaoli@foxmail.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>Dear QE experts,</div><div><br></div><div>I am studying mixed H2O/OH phase on Ag(111) using QE 6.4.1. To my suprise, however, to different computers gave totally different vibrational frequencies, with the exact same input files. Is there anybody to help me?</div><div><br></div><div>Computer A gave</div><div> freq ( 46 - 46) = 24.2 [cm-1] --> A I+R<br> freq ( 47 - 47) = 72.8 [cm-1] --> A I+R<br> freq ( 48 - 48) = 137.6 [cm-1] --> A I+R<br> freq ( 49 - 49) = 199.5 [cm-1] --> A I+R<br> freq ( 50 - 50) = 308.7 [cm-1] --> A I+R<br> freq ( 51 - 51) = 379.5 [cm-1] --> A I+R<br> freq ( 52 - 52) = 585.2 [cm-1] --> A I+R<br> freq ( 53 - 53) = 800.0 [cm-1] --> A I+R<br> freq ( 54 - 54) = 872.2 [cm-1] --> A I+R<br> freq ( 55 - 55) = 901.9 [cm-1] --> A I+R<br> freq ( 56 - 56) = 998.4 [cm-1] --> A I+R<br> freq ( 57 - 57) = 1529.7 [cm-1] --> A I+R<br> freq ( 58 - 58) = 2914.9 [cm-1] --> A I+R<br> freq ( 59 - 59) = 3064.3 [cm-1] --> A I+R<br> freq ( 60 - 60) = 3610.2 [cm-1] --> A I+R<br> </div><div>Computer B gave</div><div> freq ( 46 - 46) = 33.0 [cm-1] --> A I+R<br> freq ( 47 - 47) = 45.1 [cm-1] --> A I+R<br> freq ( 48 - 48) = 54.1 [cm-1] --> A I+R<br> freq ( 49 - 49) = 78.2 [cm-1] --> A I+R<br> freq ( 50 - 50) = 82.4 [cm-1] --> A I+R<br> freq ( 51 - 51) = 99.1 [cm-1] --> A I+R<br> freq ( 52 - 52) = 108.9 [cm-1] --> A I+R<br> freq ( 53 - 53) = 114.4 [cm-1] --> A I+R<br> freq ( 54 - 54) = 188.3 [cm-1] --> A I+R<br> freq ( 55 - 55) = 590.6 [cm-1] --> A I+R<br> freq ( 56 - 56) = 1101.8 [cm-1] --> A I+R<br> freq ( 57 - 57) = 1533.4 [cm-1] --> A I+R<br> freq ( 58 - 58) = 2812.1 [cm-1] --> A I+R<br> freq ( 59 - 59) = 3644.5 [cm-1] --> A I+R<br> freq ( 60 - 60) = 3786.8 [cm-1] --> A I+R<br></div><div><br></div><div><span lang="EN-US"><font color="#0000ff" face="Times New Roman"><b>Why the two computers give totally different results? </b></font></span></div><p align="left" style="margin:0cm 0cm 0pt;text-align:left"><font color="#0000ff" face="Times New Roman"><b><br></b></font></p><div><br></div><div> &CONTROL<br> calculation = 'scf' ,<br> restart_mode = 'from_scratch' ,<br> outdir = './' ,<br> pseudo_dir = '/home/jibiaoli/pseudo/' ,<br> prefix = 'sym' ,<br> tstress = .true. ,<br> tprnfor = .true. ,<br> /<br> &SYSTEM<br> ibrav = 0,<br> celldm(1) = 9.456004324,<br> nat = 20,<br> ntyp = 3,<br> ecutwfc = 49 ,<br> ecutrho = 411 ,<br> occupations = 'smearing' ,<br> degauss = 0.02 ,<br> smearing = 'methfessel-paxton' ,<br> vdw_corr = 'DFT-D',<br> /<br> &ELECTRONS<br> mixing_beta = 0.3 ,<br> diagonalization = 'david' ,<br> /<br>CELL_PARAMETERS alat <br> 0.866025404 0.500000000 0.000000000 <br> 0.866025404 -0.500000000 0.000000000 <br> 0.000000000 0.000000000 5.400000000 <br>ATOMIC_SPECIES<br> Ag 107.8682 Ag.pbe-n-kjpaw_psl.1.0.0.UPF <br> O 15.99940 O.pbe-n-kjpaw_psl.1.0.0.UPF <br> H 1.00800 H.pbe-kjpaw_psl.1.0.0.UPF <br>ATOMIC_POSITIONS angstrom <br>O 5.986597700 0.051902808 11.800640138<br>H 6.530086903 0.896034963 11.935550794<br>H 6.519207423 -0.788895855 11.940829013<br>O 2.800029893 0.013830142 11.748050047<br>H 3.756125095 0.022425916 11.956803063<br>Ag -0.454154628 0.136836718 9.568098196<br>Ag 5.307442766 0.123896111 9.577760992<br>Ag 2.445911493 0.129358587 9.587754292<br>Ag 2.920157088 1.499919274 7.139192063<br>Ag 1.485120252 -0.981971793 7.160426239<br>Ag 4.380244685 -0.987689704 7.134282475<br>Ag 2.889028971 -1.667975200 4.717759990 0 0 0<br>Ag 4.333537867 0.833997281 4.717759990 0 0 0<br>Ag 5.778055146 -1.667970358 4.717759990 0 0 0<br>Ag 0.000000000 0.000000000 2.358879995 0 0 0<br>Ag 5.778052352 0.000009682 2.358879995 0 0 0<br>Ag 2.889026176 0.000004841 2.358879995 0 0 0<br>Ag 2.889023381 1.667984881 0.000000000 0 0 0<br>Ag 1.444514485 -0.833987600 0.000000000 0 0 0<br>Ag 4.333540661 -0.833982759 0.000000000 0 0 0 <br>K_POINTS automatic <br> 6 6 1 0 0 0 <br></div><div><br></div><div>phonons at Gamma<br> &inputph<br> tr2_ph=1.0d-14,<br> prefix='sym',<br> alpha_mix=0.1,<br> fildyn='phG.dyn',<br> amass(1)=107.8682,<br> amass(2)=15.999,<br> amass(3)=1.0079,<br> outdir='./'<br> nat_todo=5,<br> /<br>0.0 0.0 0.0<br>1 2 3 4 5<br><br></div><div><br></div><div><div style="color:rgb(144,144,144);font-family:Arial Narrow;font-size:12px">------------------</div><div style="font-size:14px;font-family:Verdana;color:rgb(0,0,0)"><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Dr. Jibiao Li, </b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Department of Material Science and Engineering</b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Yangtze Normal University</b></font></i></div><div><i><font face="Times New Roman"><font size="2"><font color="#0000ff"><b><span style="text-align:left;text-transform:none;line-height:21px;text-indent:0px;letter-spacing:normal;font-variant:normal;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;float:none;background-color:transparent">Juxian Dadao 16#,</span> Fuling, Chongqing, China</b></font></font></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Email: <a href="mailto:jibiaoli@yznu.edu.cn" target="_blank">jibiaoli@yznu.edu.cn</a>, <a href="mailto:jibiaoli@foxmail.com" target="_blank">jibiaoli@foxmail.com</a>, <a href="mailto:jibiao.li@hotmail.com" target="_blank">jibiao.li@hotmail.com</a></b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Homepage: <a href="https://www.researchgate.net/profile/Jibiao_Li" target="_blank">https://www.researchgate.net/profile/Jibiao_Li</a></b></font></i></div>
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<a href="https://lists.quantum-espresso.org/mailman/listinfo/users" target="_blank" rel="noreferrer">https://lists.quantum-espresso.org/mailman/listinfo/users</a></blockquote></div><br clear="all"><br>-- <br><div class="gmail_signature" dir="ltr"><div dir="ltr"><div><div dir="ltr"><div>Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,<br>Univ. Udine, via delle Scienze 208, 33100 Udine, Italy<br>Phone +39-0432-558216, fax +39-0432-558222<br><br></div></div></div></div></div></div>