<div dir="auto">In theory it should be possible to obtain what you need, but it is not simple. The current open_grid code abuses some subroutine from the exact exchange calculation, which apply symmetry to wave functions but do not do any kind of k->k+G transformation to bring them inside the first unit cell. Rewriting all the machinery (with all the special cases: spin, noncolinear, parallelism, etc. ) would take a lot of time..<br><br><div data-smartmail="gmail_signature">-- <br>Lorenzo Paulatto</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Feb 5, 2022, 22:28 Zeeshan Ahmad <<a href="mailto:azeeshan@uchicago.edu">azeeshan@uchicago.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space"><span>Hi,<br></span><span><br></span><span>The open_grid.x code with automatic grid of k points in the scf input file produces k points between -0.5 and 0.5 (crystal coords). However, the EPW code requires wave functions for full set of k points from 0 to 1 in the first BZ and gives an error when using k points between -0.5 and 0.5: <br></span><span><br></span><span>Error in routine epw_setup (1):</span><span><br></span><span>coarse k-mesh needs to be strictly positive in 1st BZ <br></span><span><br></span><div>Unfortunately this is a hybrid functional calculation, so I cannot perform nscf calculation or use all k points in scf due to high memory requirement.</div><div><br></div><div>Therefore, I tried using the kpoints.x code in the PW/tools to generate IBZ k points between 0 and 1 and specified the weights in scf file. On running open_grid.x on this calculation, I get the error: </div><span><div><br></div></span><span>Error in routine exx_grid_init (1):<br>     wrong EXX q grid<br></span><span><br></span>Is it not possible to use open_grid.x other than for automatically generated k-points (runs fine in that case)? And is there a way to generate the files for full set of k-points between 0 and 1 instead of -0.5 and 0.5?<div><br></div><div>The files for reproducing the error are at: <a href="https://gitlab.com/ahzeeshan/qe-issues/-/tree/master/open_grid" target="_blank" rel="noreferrer">https://gitlab.com/ahzeeshan/qe-issues/-/tree/master/open_grid</a></div><div><br></div><div>I used a 4 by 4 by 2 grid of k-points to generate the IBZ using kpoints.x code.</div><div><br></div><div>Thanks for your help,</div><div>Zeeshan</div><div><span><div><br></div></span><span><div><br></div></span><span><div><br></div></span><span><br></span><span><div>
<div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space">--<br><span style="font-style:normal"><font face="Arial" size="1">Zeeshan Ahmad</font></span></div><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><span style="font-style:normal"><font face="Arial" size="1">Postdoctoral Scholar<br>Pritzker School of Molecular Engineering<br>The University of Chicago</font></span></div><div dir="auto" style="text-align:start;text-indent:0px;word-wrap:break-word;line-break:after-white-space"><font face="Arial" size="1"></font></div></div></div></div></div></div></div></div></div>
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