<div data-ntes="ntes_mail_body_root" style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><div style="margin:0;">Dear Quantum ESPRESSO Developers£º</div><div style="margin:0;">I have recently encountered an unsolvable bug while calculating superconductivity for a certain material system using EPW. The settings in my ¡®nscf.in¡¯ file are:</div><div style="margin:0;"><span style="background-color: rgb(255, 255, 255); color: rgb(221, 64, 50);">nscf.in</span></div><div style="margin:0;">&control</div><div style="margin:0;"> calculation = 'bands',</div><div style="margin:0;"> prefix = 'NbMgB4',<span style="background-color: rgb(255, 255, 255);"></span><span style="background-color: rgb(255, 255, 255); color: rgb(221, 64, 50);"></span></div><div style="margin:0;"> pseudo_dir = '../',</div><div style="margin:0;"> outdir = './',</div><div style="margin:0;"> wf_collect = .true.,</div><div style="margin:0;"> verbosity='high'</div><div style="margin:0;"> /</div><div style="margin:0;"> &system </div><div style="margin:0;"> ibrav = 0,</div><div style="margin:0;"> nat = 6,</div><div style="margin:0;"> ntyp = 3,</div><div style="margin:0;"> ecutwfc = 65,</div><div style="margin:0;"> ecutrho = 600.0,</div><div style="margin:0;"> smearing = 'mp',</div><div style="margin:0;"> occupations = 'smearing',</div><div style="margin:0;"> !nosym = .true.,</div><div style="margin:0;"> !noinv = .true.,</div><div style="margin:0;"> degauss = 0.05</div><div style="margin:0;">/</div><div style="margin:0;">&electrons </div><div style="margin:0;"> diagonalization = 'david',</div><div style="margin:0;"> mixing_mode = 'plain',</div><div style="margin:0;"> mixing_beta = 0.3,</div><div style="margin:0;"> conv_thr = 1.0d-8</div><div style="margin:0;"> /</div><div style="margin:0;"> ATOMIC_SPECIES</div><div style="margin:0;"> Mg 24.305 Mg.pbesol-n-kjpaw_psl.0.3.0.UPF</div><div style="margin:0;"> Nb 92.91 Nb.pbesol-spn-kjpaw_psl.0.3.0.UPF</div><div style="margin:0;"> B 10.811 b_pbesol_v1.4.uspp.F.UPF</div><div style="margin:0;"><br></div><div style="margin:0;">CELL_PARAMETERS {bohr}</div><div style="margin:0;"> 5.7979 0.00000 0.00000</div><div style="margin:0;"> 0.00000 10.146 0.00000</div><div style="margin:0;"> 0.00000 0.00000 6.3104</div><div style="margin:0;"><br></div><div style="margin:0;"> ATOMIC_POSITIONS crystal</div><div style="margin:0;">Mg -0.0000000000000000 0.0000000000000000 -0.0000000000000000</div><div style="margin:0;">Nb 0.5000000000000000 0.5000000000000000 -0.0000000000000000</div><div style="margin:0;">B -0.0000000000000000 0.3322622395511202 0.5000000000000000</div><div style="margin:0;">B 0.5000000000000000 0.8331863993084528 0.5000000000000000</div><div style="margin:0;">B -0.0000000000000000 0.6677377894488785 0.5000000000000000</div><div style="margin:0;">B 0.5000000000000000 0.1668135716915483 0.5000000000000000</div><div style="margin:0;"><br></div><div style="margin:0;">K_POINTS crystal
</div><div style="margin:0;">216
</div><div style="margin:0;"> 0.00000000 0.00000000 0.00000000 4.629630e-03
</div><div style="margin:0;"> 0.00000000 0.00000000 0.16666667 4.629630e-03
</div><div style="margin:0;"> 0.00000000 0.00000000 0.33333333 4.629630e-03</div><div style="margin:0;"> ......</div><div style="margin:0;"> 0.83333333 0.83333333 0.50000000 4.629630e-03
</div><div style="margin:0;"> 0.83333333 0.83333333 0.66666667 4.629630e-03
</div><div style="margin:0;"> 0.83333333 0.83333333 0.83333333 4.629630e-03 <span style="color: rgb(221, 64, 50);">(which were generated using ¡®kmesh.pl¡¯ 6¡Á6¡Á6)</span></div><div style="margin:0;"><br></div><div style="margin:0;">For the phonon calculation, my ¡®<span style="color: rgb(221, 64, 50);">ph.in</span>¡¯ file is:</div><div style="margin:0;">&inputph</div><div style="margin:0;"> prefix='NbMgB4',</div><div style="margin:0;"> fildyn='NbMgB4.dyn.xml',</div><div style="margin:0;"> fildvscf='dvscf',</div><div style="margin:0;"> tr2_ph=1.0d-10,</div><div style="margin:0;"> ldisp=.true.,</div><div style="margin:0;"> nq1 = 3,</div><div style="margin:0;"> nq2 = 3,</div><div style="margin:0;"> nq3 = 3,</div><div style="margin:0;"> /</div><div style="margin:0;">And some relevant parameters in my ¡®<span style="color: rgb(221, 64, 50);">epw.in</span>¡¯ file are:</div><div style="margin:0;">mp_mesh_k = .true.</div><div style="margin:0;">use_ws = .true.</div><div style="margin:0;"> nk1 = 6</div><div style="margin:0;"> nk2 = 6</div><div style="margin:0;"> nk3 = 6</div><div style="margin:0;"> nq1 = 3</div><div style="margin:0;"> nq2 = 3</div><div style="margin:0;"> nq3 = 3</div><div style="margin:0;"> nkf1 = 12</div><div style="margin:0;"> nkf2 = 12</div><div style="margin:0;"> nkf3 = 12</div><div style="margin:0;"> nqf1 = 6</div><div style="margin:0;"> nqf2 = 6</div><div style="margin:0;"> nqf3 = 6</div><div style="margin:0;">/</div><div style="margin:0;">After submitting the epw job, I get the error: <span style="color: rgb(221, 64, 50);">Error in routine createkmap (1): is this a uniform k-mesh?</span></div><div style="margin:0;">Then I set <span style="color: rgb(221, 64, 50);">¡®¡¯nosym = .true.¡®¡¯</span> in the ¡®nscf.in¡¯ file. then I get:</div><div style="margin:0;">= BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES</div><div style="margin:0;">= RANK 0 PID 6279 RUNNING AT d111</div><div style="margin:0;">= KILLED BY SIGNAL: 6 (Aborted)</div><div style="margin:0;">After that, I removed ¡®¡¯nosym=.true.¡®¡¯ from
¡®nscf.in¡¯ , but EPW again reports the ¡®¡¯is this a uniform k-mesh?¡®¡¯ error. If I instead use ¡®¡¯K_POINTS automatic¡®¡¯ in
nscf.in¡¯ as£º</div><div style="margin:0;">K_POINTS automatic</div><div style="margin:0;">6 6 6 0 0 0</div><div style="margin:0;">then the error becomes: <span style="color: rgb(221, 64, 50);">inconsistent nscf and elph k-grids</span></div><div style="margin:0;"><span style="color: rgb(221, 64, 50);">other methods such as£º</span></div><div style="margin:0;"><div style="margin: 0px;"><span style="color: rgb(221, 64, 50);">1.K_POINTS automatic</span></div><div style="margin: 0px;"><span style="color: rgb(221, 64, 50);">6 6 6 1 1 1</span></div></div><div style="margin:0;"><span style="color: rgb(221, 64, 50);">2.Modify the grid density of k-points and q-points.</span></div><div style="margin:0;"><span style="color: rgb(221, 64, 50);">3.Comment out this line£ºmp_mesh_k = .true.</span></div><div style="margin:0;"><span style="color: rgb(221, 64, 50);">are unable to solve the problem.</span></div><div style="margin:0;">No matter what I try, these errors persist. Could you please help me analyze the cause? Thank you very much for your attention!</div><div style="margin:0;">Yours </div><div style="margin:0;"> Yandong Yang </div><div style="margin:0;"><br></div><div style="margin:0;"><br></div></div>