<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hello,<div class=""><br class=""></div><div class="">I have read somewhere that the k-point grid and the q-grid have to be commensurate with one another. For instance, if your q-grid is 2x2x2 the k-point one could be 2x2x2, 4x4x4, 8x8x8, 10x10x10, 12x12x12 etc.</div><div class=""><br class=""></div><div class="">HTH,</div><div class="">Pascal</div><div class=""><br class=""></div><div class=""><br class=""><div class="">
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font-family: Mistral;">Pascal Boulet</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><font face="Lucida Handwriting" class=""><span class="" style="font-size: 21px;">—</span></font></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><em class="" style="color: rgb(34, 187, 234); font-family: verdana; font-size: 11px; line-height: 22px;">Professor in computational materials chemistry - DEPARTMENT OF CHEMISTRY</em></div><div class=""><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px; font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif; font-size: 15px; line-height: 22px;"><span class="" style="font-size: 11px; font-family: verdana;">University of Aix-Marseille </span><span class="" style="font-size: 11px; font-family: verdana;">- Avenue Escadrille Normandie Niemen - F-13013 Marseille - FRANCE</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px; font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif; font-size: 15px; line-height: 22px;"><span class="" style="font-size: 11px; font-family: verdana;">Tél: +33(0)4 13 55 18 10 - Fax : +33(0)4 13 55 18 50</span></div><div class="" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;"><font face="verdana" class=""><span class="" style="font-size: 12px; line-height: 22px;">Email : </span></font><font color="#22bbea" face="verdana" class=""><span style="font-size: 12px; 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<div><br class=""><blockquote type="cite" class=""><div class="">Le 19 oct. 2021 à 04:53, 4120109024李晨纲 via users <<a href="mailto:users@lists.quantum-espresso.org" class="">users@lists.quantum-espresso.org</a>> a écrit :</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=GB18030" class="">Dear researchers：<br class="">Hello, everyone. Let me ask you a question about EPW.<br class=""><div class="">First，this is the pw, EPW version and phonon version I use：</div><div class=""><br class=""></div><div class="">Program PWSCF v.6.8 starts on 19Oct2021 at 10:47:42 <br class=""></div><div class="">Program EPW v.5.4 starts on 19Oct2021 at 10:41:49</div><div class="">Program PHONON v.6.8 starts on 19Oct2021 at 10:42:21 <br class=""></div><div class=""><br class=""></div><div class="">Now，I am learning to use the BTE method with electroacoustic coupling to calculate the mobility of w-GaN, but the following error occurs in the calculation using Wannier interpolation in “epw1.out" ：</div><div class=""><br class=""></div><div class=""> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br class=""> Error in routine createkmap (1):<br class=""> q-vec not commensurate<br class=""> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">My "epw1. In" file is as follows:</div><div class="">-<br class="">&inputepw<br class=""> prefix = 'gan'<br class=""> amass(1) = 69.723<br class=""> amass(2) = 14.007<br class=""> outdir = './'<br class=""><br class=""> iverbosity = 0<br class=""><br class=""> elph = .true.<br class=""> epbwrite = .true.<br class=""> epbread = .false.<br class=""> epwwrite = .true.<br class=""> epwread = .false.<br class=""> etf_mem = 1<br class=""> vme = 'wannier'<br class=""><br class=""> lpolar = .true.<br class=""> lifc = .false.<br class=""> asr_typ = 'simple'<br class=""> use_ws = .false.<br class=""> lphase = .true.<br class=""><br class=""> nbndsub = 14<br class=""> bands_skipped = 'exclude_bands = 1-12'<br class=""><br class=""> wannierize = .true.<br class=""> num_iter = 1500<br class=""> iprint = 3<br class=""> dis_win_max = 25.5<br class=""> dis_win_min = 2.2<br class=""> dis_froz_max= 14.5<br class=""> proj(1) = 'Ga:sp3'<br class=""> proj(2) = 'N:p'<br class=""> wdata(1) = 'bands_plot = .true.'<br class=""> wdata(2) = 'begin kpoint_path'<br class=""> wdata(3) = 'G 0.00 0.00 0.00 M 0.50 0.00 0.00'<br class=""> wdata(4) = 'G 0.00 0.00 0.00 K 0.33333333333 0.33333333333 0.00'<br class=""> wdata(5) = 'G 0.00 0.00 0.00 A 0.00 0.00 0.50'<br class=""> wdata(6) = 'end kpoint_path'<br class=""> wdata(7) = 'bands_plot_format = gnuplot'<br class=""> wdata(8) = 'guiding_centres = .true.'<br class=""> wdata(9) = 'dis_num_iter = 1000'<br class=""> wdata(10) = 'num_print_cycles = 10'<br class=""> wdata(11) = 'dis_mix_ratio = 1.0'<br class=""> wdata(12) = 'conv_tol = 1E-8'<br class=""> wdata(13) = 'conv_window = 4'<br class=""><br class=""> elecselfen = .false.<br class=""> phonselfen = .false.<br class=""> a2f = .false.<br class=""><br class=""> fsthick = 100.0 ! eV<br class=""> temps = 1 ! K<br class=""> degaussw = 0.01 ! eV<br class=""><br class=""> dvscf_dir = './save/'<br class=""><br class=""> efermi_read = .true<br class=""> fermi_energy= 11.80<br class=""> band_plot = .true.<br class=""><br class=""> filkf = './MGA.txt'<br class=""> nqf1 = 1<br class=""> nqf2 = 1<br class=""> nqf3 = 1<br class=""><br class=""> nk1 = 2<br class=""> nk2 = 2<br class=""> nk3 = 2<br class=""> nq1 = 4<br class=""> nq2 = 4<br class=""> nq3 = 4<br class=""> /<br class=""> <br class=""></div><div class="">I have ensured that my phonon calculation uses a 4x4x4 grid and that the nscf calculation uses a 2x2x2 path. The following are the inputs of these two files</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">---<br class=""> &inputph<br class=""> tr2_ph=1.0d-14,<br class=""> prefix='gan',<br class=""> amass(1)=69.723,<br class=""> amass(2)=14.007,<br class=""> outdir='./',<br class=""> fildyn='gan.dyn',<br class=""> fildvscf='dvscf'<br class=""> ldisp=.true.,<br class=""> epsil=.true.,<br class=""> nq1=4, nq2=4, nq3=4<br class=""> /<br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">&control<br class=""> calculation='nscf'<br class=""> prefix='gan'<br class=""> restart_mode='from_scratch'<br class=""> pseudo_dir='./'<br class=""> outdir='./'<br class=""> tprnfor=.true.<br class=""> tstress=.true.<br class=""> wf_collect = .true.<br class=""> verbosity = 'high'<br class=""> /<br class=""> &system<br class=""> ibrav = 4<br class=""> celldm(1)= 5.9612<br class=""> celldm(3)= 1.6299<br class=""> nat = 4<br class=""> ntyp = 2<br class=""> ecutwfc = 40<br class=""> nbnd = 30<br class=""> /<br class=""> &electrons<br class=""> diagonalization='david'<br class=""> mixing_beta=0.7<br class=""> conv_thr=1.0d-10<br class=""> diago_full_acc = .true.<br class=""> /<br class="">ATOMIC_SPECIES<br class=""> Ga 69.723 Ga-LDA.upf<br class=""> N 14.007 N-LDA.upf<br class="">ATOMIC_POSITIONS crystal<br class=""> Ga 0.666666666667 0.333333333333 0.0<br class=""> N 0.666666666667 0.333333333333 0.376458<br class=""> Ga 0.333333333333 0.666666666667 0.5<br class=""> N 0.333333333333 0.666666666667 0.876458<br class="">K_POINTS crystal<br class="">8<br class="">0.0 0.0 0.0 0.125<br class="">0.0 0.0 0.5 0.125<br class="">0.0 0.5 0.0 0.125<br class="">0.0 0.5 0.5 0.125<br class="">0.5 0.0 0.0 0.125<br class="">0.5 0.0 0.5 0.125<br class="">0.5 0.5 0.0 0.125<br class="">0.5 0.5 0.5 0.125<br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Thank you for your attention and look forward to your answers！！！<br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div>_______________________________________________<br class="">Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu" class="">www.max-centre.eu</a>)<br class="">users mailing list <a href="mailto:users@lists.quantum-espresso.org" class="">users@lists.quantum-espresso.org</a><br class=""><a href="https://lists.quantum-espresso.org/mailman/listinfo/users" class="">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div></blockquote></div><br class=""></div></body></html>