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<p><font size="-1">Dear Yunzhe <br>
</font></p>
<p><font size="-1"><br>
</font></p>
<p><font size="-1">if your kpoint are provided as a list, the
k-point set has the right symmetry and the proportions between
the weights is the right one, maybe you can try using nosym =
.true. and use_all_frac = .true. <br>
</font></p>
<p><font size="-1"><br>
</font></p>
<p><font size="-1"><br>
</font></p>
<div class="moz-cite-prefix">On 15/11/18 19:30, Yunzhe Wang wrote:<br>
</div>
<blockquote type="cite"
cite="mid:SN2PR01MB207937F49F85F81EA144BF0488DC0@SN2PR01MB2079.prod.exchangelabs.com">
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dir="ltr">
<p style="margin-top:0;margin-bottom:0">Dear Professor
Giannozzi,</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">I agree that additional
flags will unnecessarily increase the complexity to maintain.
My original thought is to not disturb the original behavior
of pw.x.</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
The easier way to stop the expansion by lattice is to change
the line 553 of setup.f90 (github) from</p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
CALL irreducible_BZ(nrot, s, nsym ...)</p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
to </p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
CALL irreducible_BZ(nsym + nsym_na, s,
nsym ....)</p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
<br>
</p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
The original code is to expand by the lattice point group, and
the latter is to expand by the crystal point group, with the
discarded glide plane / screw axis included. Our server
doesn't have the prior knowledge of the FFT grid used in pw.x
and therefore returns the k-points in IBZ of the crystal. If
pw.x decides to throw away some symmetry, the IBZ should be
enlarged to the lower symmetry one, hence with the "+nsym_na"
part.</p>
<p style="font-family: Calibri, Helvetica, sans-serif,
EmojiFont, "Apple Color Emoji", "Segoe UI
Emoji", NotoColorEmoji, "Segoe UI Symbol",
"Android Emoji", EmojiSymbols; font-size: 16px;">
<br>
</p>
<p style="margin-top:0;margin-bottom:0">An example would be the
one that an actual user reported to us during the beta
testing:</p>
<p style="margin-top:0;margin-bottom:0">The structure is SiC,
which she downloaded from ICSD data base. It's hexagonal with
12 atoms in the unit cell, but due to the limited precision
that ICSD has (to 10^-4 Angstrom), both pw.x and our server
detected it as an orthorhombic structure. Our server returned
a mesh with 14 asymmetrical k-points, and QE expanded it, with
the point group of a hexagonal lattice, to 84
distinct k-points. The total energies are -394.9476363 Ry and
-394.9476383 Ry (a difference of 0.002 mRy) , with the
expansion by pw.x shut off and switch on respectively. And the
calculation time on 12 processors are 1.55 minutes (14
k-points) and 8.43 minutes (k-points), respectively. </p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">I know in actual serious
calculation for publication, the atomic positions would be
much precise, and symmetry will be inspected. But a similar
case would still be present if a user is working on a slab or
a supercell which the crystal symmetry and the unit cell
symmetry are very different. An expansion by the lattice point
group, will increase the calculation time by a lot. Also, for
low symmetry structure, the k-points will increase, averagely,
by 1/5 - 1/3, in serveral test cases.</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">I attached below the
input file for the SiC for your reference (the
pseudo-potential files are not attached):</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>&CONTROL</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> calculation = 'scf' , </div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> pseudo_dir = './' ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> disk_io = 'none' ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> verbosity = 'high',</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>/</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>&SYSTEM</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> ibrav = 0 ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> ntyp = 2 , </div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> nat = 12 , </div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> occupations = 'smearing' ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> smearing = 'marzari-vanderbilt' ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> degauss = 0.02 ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> ecutwfc = 50 ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>/</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>&ELECTRONS</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> startingwfc = 'random' ,</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>/</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>&IONS</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>/</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>&CELL</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>/</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>CELL_PARAMETERS bohr</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> 5.82224621542067 0.00000000000000 0.00000000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> -2.91112310771033 5.04221312964210 0.00000000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> 0.00000000000000 0.00000000000000 28.58172981466878</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>ATOMIC_SPECIES</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 28.0855 Si.GGA-PBE-paw.UPF</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 12.0107 C.pbe-rrkjus.UPF</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>ATOMIC_POSITIONS crystal</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 1.00000000000000 1.00000000000000 0.50000000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 0.00000000000000 0.00000000000000 0.00000000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 0.66670000000000 0.33340000000000 0.66640000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 0.33330000000000 0.66660000000000 0.16640000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 0.33330000000000 0.66660000000000 0.83290000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> Si 0.66670000000000 0.33340000000000 0.33290000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 0.66670000000000 0.33340000000000 0.54120000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 0.33330000000000 0.66660000000000 0.04120000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 0.33330000000000 0.66660000000000 0.70800000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 0.66670000000000 0.33340000000000 0.20800000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 0.00000000000000 0.00000000000000 0.87460000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div> C 0.00000000000000 0.00000000000000 0.37460000000000</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div><br>
</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div># Server version 2018.08.08. ||BETA_MODE|| K-points
for C1Si1 with MINDISTANCE=20.0 Angstroms and
INCLUDEGAMMA=AUTO FORCEDIAGONAL=false has 112 total points
and 14 distinct points. Effective minDistance
21.34579415247883 Angstroms.</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>K_POINTS crystal</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>14</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.07142857142857 0.90178571428571 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.21428571428571 0.70535714285714 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.35714285714286 0.50892857142857 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.50000000000000 0.31250000000000 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.64285714285714 0.11607142857143 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.92857142857143 0.72321428571429 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.07142857142857 0.52678571428571 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.21428571428571 0.33035714285714 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.50000000000000 0.93750000000000 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.64285714285714 0.74107142857143 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.07142857142857 0.15178571428571 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.21428571428571 0.95535714285714 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.64285714285714 0.36607142857143 0.25000000000000 8.0</div>
</blockquote>
<blockquote style="margin: 0 0 0 40px; border: none; padding:
0px;">
<div>0.21428571428571 0.58035714285714 0.25000000000000 8.0</div>
</blockquote>
</blockquote>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
</div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
face="Calibri, sans-serif" color="#000000"><b>From:</b> Paolo
Giannozzi <a class="moz-txt-link-rfc2396E" href="mailto:p.giannozzi@gmail.com"><p.giannozzi@gmail.com></a><br>
<b>Sent:</b> Thursday, November 15, 2018 9:04:03 AM<br>
<b>To:</b> General discussion list for Quantum ESPRESSO
developers<br>
<b>Cc:</b> Yunzhe Wang<br>
<b>Subject:</b> Re: [QE-developers] Patch to modify the pw.x
behavior at user-provided k-point list</font>
<div> </div>
</div>
<div>
<div dir="ltr">
<div>Dear Yunzhe</div>
<div><br>
</div>
<div>as a rule I am against adding new input variables - there
are already hundreds of them - unless there are no
alternatives. From what I understand, your procedure
produces a list of k-points that are already in the
Brillouin Zone reduced using the symmetry of the crystal. If
so, the best solution is to ensure that the code does not
spoil it when computing the actual k-point grid from the
input k-point grid. It would be useful to have a few
examples showing what happens. </div>
<div><br>
</div>
<div>Paolo<br>
</div>
<br>
<div>
<div class="x_gmail_quote">
<div dir="ltr">On Wed, Nov 14, 2018 at 8:26 AM Yunzhe Wang
<<a href="mailto:ywang393@jhu.edu" target="_blank"
moz-do-not-send="true">ywang393@jhu.edu</a>> wrote:<br>
</div>
<blockquote class="x_gmail_quote" style="margin:0 0 0
.8ex; border-left:1px #ccc solid; padding-left:1ex">
<div dir="ltr">
<div
id="x_m_-1999253779495694799m_660957958707217870divtagdefaultwrapper"
dir="ltr" style="font-size:12pt; color:rgb(0,0,0);
font-family:Calibri,Helvetica,sans-serif,EmojiFont,"Apple
Color Emoji","Segoe UI
Emoji",NotoColorEmoji,"Segoe UI
Symbol","Android Emoji",EmojiSymbols">
<p style="margin-top:0; margin-bottom:0">Dear
Professors and Developers,</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0">Sorry about
the bothering long mail!</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0">Our group
has built a server to generate the least-number
k-point mesh for a user-given length of the
corresponding supercell size. (By "corresponding",
I mean a calculation with a dense k-point mesh for
a primitive cell, is equivalent to, a calculation
with a large supercell with 1 k-point). Currently,
the server is able to read the user input file and
append the returned K_POINTS card at the end.</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0">However,
during the beta testing, we found that QE had the
subroutine irreducible_BZ() to force the mesh
being expand by the lattice point symmetries
first, and then being reduced by the true crystal
symmetry. Our server already returns a mesh
complying with the crystal symmetry, but will be
expanded quite a lot (even more in the low
symmetry case) by irreducible_BZ(). </p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0">So my
question is, is there a specific reason to let the
mesh being expanded by the lattice symmetry first?
Our beta test results show the two cases, expanded
and not-expanded (initial K_POINTS card in both
cases provided by our server), has nearly the
same total energy. And the converged energy by the
not-expanded one is also very close to that of the
MP generated k-point mesh.</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0">We have
wrote a small patch to include an additional flag
"kpuser" to switch on and off the expansion, and
when it's off, we leave the behavior of QE
untouched. Do you think it's ok that we release
the patch and let users of our server to patch
their local QE distribution? Or we open an issue
on QE and let the experts of QE to scrutinize this
feature, if you think it's valuable to be
incorporated in?</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0">Best
Regards,</p>
<p style="margin-top:0; margin-bottom:0">Yunzhe(Phil)
Wang, <span style="font-size:12pt">Graduate
Student</span></p>
<p style="margin-top:0; margin-bottom:0">Mueller
Research Group,</p>
<p style="margin-top:0; margin-bottom:0">Johns
Hopkins University</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
<p style="margin-top:0; margin-bottom:0"><br>
</p>
</div>
</div>
_______________________________________________<br>
developers mailing list<br>
<a href="mailto:developers@lists.quantum-espresso.org"
target="_blank" moz-do-not-send="true">developers@lists.quantum-espresso.org</a><br>
<a
href="https://lists.quantum-espresso.org/mailman/listinfo/developers"
rel="noreferrer" target="_blank"
moz-do-not-send="true">https://lists.quantum-espresso.org/mailman/listinfo/developers</a><br>
</blockquote>
</div>
<br clear="all">
<br>
-- <br>
<div dir="ltr"
class="x_m_-1999253779495694799gmail_signature">
<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>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
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