<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: style=" font-size:="" 12pt;="" color:="" #000000"=""><div><br></div><div><div>Dear Xin Jin,</div><div><br></div><div> Sorry that I have another matter to discuss. If you wish we may start a separate thread on the subject I am eager to discuss. I have some concern about your script. If you want to do calculation for BCC W you may need to use ibrav=3. Note that for ibrav=3 the (primitive) lattice vectors are in the form:</div><div><br></div><div>ibrav=3 cubic I (bcc)</div><div> v1 = (a/2)(1,1,1), v2 = (a/2)(-1,1,1), v3 = (a/2)(-1,-1,1) which is inbuilt in QE (so that you need not input CELL_PARAMETERS) and you only need to put an atom in the position 0.00 0.00 0.00.</div><div>With those input QE determines the k_points for BCC Bravais Lattice.</div><div><br></div><div>You have input the atomic positions in terms of supercell made of BCC unit cell. And you have put ibrav=0. With those input I am afraid most probably the k_points generated would be that of a Simple Cubic structure.</div><div>What we can do is next week I would generate the k_points for BCC with a mesh of 4 4 4 0 0 0 and post it. And you can see whether it is matching with the k_points considered in your calculation and discuss further.</div><div><br></div><div>Thank you,</div><div>Best regards,</div><div>Krishnendu</div></div><div><br></div><div>------------------------------------------------------------------------------------------------------------------------------------------</div><div><br data-mce-bogus="1"></div><div><div>Xin Jin wrote on 28/Oct/2022 </div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Dear Quantum Espresso Forum,</div><div><br></div><div>I encountered a problem related to the parallel computing using QE7.1 </div><div>for vc-relax.</div><div><br></div><div>I was trying to perform a vc-relax for a 3*3*3 BCC tungsten super cell. </div><div>The code works fine for non-parallel computing, also works fine for </div><div>parallel computing if the number of processors is smaller than 10.</div><div><br></div><div>However, if the number of processors is larger than 10, I will get </div><div>following MPI error:</div><div>/*** An error occurred in MPI_Comm_free//</div><div>//*** reported by process [3585895498,2]//</div><div>//*** on communicator MPI_COMM_WORLD//</div><div>//*** MPI_ERR_COMM: invalid communicator//</div><div>//*** MPI_ERRORS_ARE_FATAL (processes in this communicator will now abort,//</div><div>//*** and potentially your MPI job)/</div><div><br></div><div>For parallel computing, I am using /OpenMPI/3.1.4-gcccuda/. (In </div><div>addition, it seems that If I use OpenMPI V4, the simulation speed will </div><div>be much slower than that of V3.)</div><div><br></div><div>Another thing is that, if I decrease the size of the supper cell, for </div><div>example to 2*2*2, then there is no problem in the parallel computing </div><div>even if I use more than 30 processors.</div><div><br></div><div>Could you help me look at this problem, please?</div><div><br></div><div>The input for QE can be found below.</div><div><br></div><div>Thank you in advance!</div><div><br></div><div>Xin Jin</div><div><br></div><div>/&control//</div><div>//</div><div>// calculation='vc-relax' //</div><div>// restart_mode='from_scratch', //</div><div>// prefix='W_relax', //</div><div>// pseudo_dir="../../PP_files",//</div><div>// outdir='./'//</div><div>//</div><div>// ///</div><div>////</div><div>//</div><div>// &system//</div><div>// ibrav= 0, //</div><div>// celldm(1)=5.972,//</div><div>// nat= 54, //</div><div>// ntyp= 1,//</div><div>// ecutwfc = 50,//</div><div>// ecutrho = 500,//</div><div>// occupations='smearing', smearing='mp', degauss=0.06//</div><div>// ///</div><div>//</div><div>// &electrons//</div><div>// diagonalization='david',//</div><div>// conv_thr = 1.0d-8,//</div><div>// mixing_beta = 0.5,//</div><div>// ///</div><div>////</div><div>// &ions//</div><div>// ///</div><div>//</div><div>// &cell//</div><div>// press = 0.0,//</div><div>// ///</div><div>////</div><div>//ATOMIC_SPECIES//</div><div>// W 183.84 W.pbe-spn-kjpaw_psl.1.0.0.UPF//</div><div>////</div><div>//CELL_PARAMETERS {alat}//</div><div>// 3.0 0.0 0.0//</div><div>// 0.0 3.0 0.0//</div><div>// 0.0 0.0 3.0 //</div><div>////</div><div>//ATOMIC_POSITIONS {alat}//</div><div>//W 0.00000 0.00000 0.00000//</div><div>//W 0.50000 0.50000 0.50000//</div><div>//W 1.00000 0.00000 0.00000//</div><div>//W 1.50000 0.50000 0.50000//</div><div>//W 2.00000 0.00000 0.00000//</div><div>//W 2.50000 0.50000 0.50000//</div><div>//W 0.00000 1.00000 0.00000//</div><div>//W 0.50000 1.50000 0.50000//</div><div>//W 1.00000 1.00000 0.00000//</div><div>//W 1.50000 1.50000 0.50000//</div><div>//W 2.00000 1.00000 0.00000//</div><div>//W 2.50000 1.50000 0.50000//</div><div>//W 0.00000 2.00000 0.00000//</div><div>//W 0.50000 2.50000 0.50000//</div><div>//W 1.00000 2.00000 0.00000//</div><div>//W 1.50000 2.50000 0.50000//</div><div>//W 2.00000 2.00000 0.00000//</div><div>//W 2.50000 2.50000 0.50000//</div><div>//W 0.00000 0.00000 1.00000//</div><div>//W 0.50000 0.50000 1.50000//</div><div>//W 1.00000 0.00000 1.00000//</div><div>//W 1.50000 0.50000 1.50000//</div><div>//W 2.00000 0.00000 1.00000//</div><div>//W 2.50000 0.50000 1.50000//</div><div>//W 0.00000 1.00000 1.00000//</div><div>//W 0.50000 1.50000 1.50000//</div><div>//W 1.00000 1.00000 1.00000//</div><div>//W 1.50000 1.50000 1.50000//</div><div>//W 2.00000 1.00000 1.00000//</div><div>//W 2.50000 1.50000 1.50000//</div><div>//W 0.00000 2.00000 1.00000//</div><div>//W 0.50000 2.50000 1.50000//</div><div>//W 1.00000 2.00000 1.00000//</div><div>//W 1.50000 2.50000 1.50000//</div><div>//W 2.00000 2.00000 1.00000//</div><div>//W 2.50000 2.50000 1.50000//</div><div>//W 0.00000 0.00000 2.00000//</div><div>//W 0.50000 0.50000 2.50000//</div><div>//W 1.00000 0.00000 2.00000//</div><div>//W 1.50000 0.50000 2.50000//</div><div>//W 2.00000 0.00000 2.00000//</div><div>//W 2.50000 0.50000 2.50000//</div><div>//W 0.00000 1.00000 2.00000//</div><div>//W 0.50000 1.50000 2.50000//</div><div>//W 1.00000 1.00000 2.00000//</div><div>//W 1.50000 1.50000 2.50000//</div><div>//W 2.00000 1.00000 2.00000//</div><div>//W 2.50000 1.50000 2.50000//</div><div>//W 0.00000 2.00000 2.00000//</div><div>//W 0.50000 2.50000 2.50000//</div><div>//W 1.00000 2.00000 2.00000//</div><div>//W 1.50000 2.50000 2.50000//</div><div>//W 2.00000 2.00000 2.00000//</div><div>//W 2.50000 2.50000 2.50000//</div><div>//</div><div>//K_POINTS {automatic}//</div><div>//4 4 4 0 0 0//</div><div>/</div><div>-------------- next part --------------</div><div>An HTML attachment was scrubbed...</div><div>URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20221028/87b8c648/attachment.html></div></div><div><br></div><div data-marker="__SIG_PRE__"></div></div></body>
<br>
<br></html>