Dear professor Jianxin Zhu,<br><br>Thank you so much for your quick reply.<br><br>Enlarging RKmax solves the problem! I found I have to set RKmax=9 which is pretty large compared to default 7 to completely eliminate all sawtooth artifacts in bands.<br><br>But I still want to know why a smaller RKmax would cause eigenvalues to be discontinuous (in essence hamiltonian is discontinuous) at several k points.<br><br>best regards<div><br></div><div><div><br></div><div><br></div><div style="font-size: 12px;font-family: Arial Narrow;padding:2px 0 2px 0;">------------------ Original ------------------</div><div style="font-size: 12px;background:#efefef;padding:8px;"><div><b>From:</b> "A Mailing list for WIEN2k users" <jxzhu@lanl.gov>;</div><div><b>Date:</b> Fri, Jan 22, 2021 11:57 PM</div><div><b>To:</b> "A Mailing list for WIEN2k users"<wien@zeus.theochem.tuwien.ac.at>;<wbr></div><div></div><div><b>Subject:</b> Re: [Wien] [EXTERNAL] Bands are often not smooth when zoom in</div></div><div><br></div>
<div style="direction:ltr">What rkmax value are you using? Usually a larger rkmax helps make the bands smooth.</div>
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<div style="direction:ltr">Jianxin</div>
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<div class="gw_quote" style="border-top:#b5c4df 1pt solid; padding-top:6px; font-size:14px">
<div><b>From: </b><span>Wien <<a href="mailto:wien-bounces@zeus.theochem.tuwien.ac.at">wien-bounces@zeus.theochem.tuwien.ac.at</a>> on behalf of: 巴拉比 <<a href="mailto:balabi@qq.com">balabi@qq.com</a>></span></div>
<div><b>Date: </b><span>Friday, Jan 22, 2021, 8:15 AM</span></div>
<div><b>To: </b><span>wien <<a href="mailto:wien@zeus.theochem.tuwien.ac.at">wien@zeus.theochem.tuwien.ac.at</a>></span></div>
<div><b>Subject: </b><span>[EXTERNAL] [Wien] Bands are often not smooth when zoom in</span></div>
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<div>Dear wien2k developers,</div>
<div><br>
</div>
<div>I found bands obtained from wien2k are often not smooth and have many small sawtooth bumps especially when you zoom in. I can reproduce this kind of band artifacts in version 19.2 and 17.1, on differnet computers and link to different version of MKL. I'll
take simple copper as an example to show how I obtain the bands:</div>
<div><br>
</div>
<div>the structure file I use is as:</div>
<div><br>
</div>
<div>blebleble <br>
F LATTICE,NONEQUIV.ATOMS: 1 225 Fm-3m <br>
RELA <br>
6.872726 6.872726 6.872726 90.000000 90.000000 90.000000 <br>
ATOM 1: X=0.00000000 Y=0.00000000 Z=0.00000000<br>
MULT= 1 ISPLIT= 2<br>
Cu1 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 29.0 <br>
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000<br>
0.0000000 1.0000000 0.0000000<br>
0.0000000 0.0000000 1.0000000<br>
48 NUMBER OF SYMMETRY OPERATIONS<br>
1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
0 0 1 0.00000000<br>
1<br>
-1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
0 0 1 0.00000000<br>
2<br>
-1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
0 0-1 0.00000000<br>
3<br>
1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
0 0-1 0.00000000<br>
4<br>
0 0 1 0.00000000<br>
1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
5<br>
0 0 1 0.00000000<br>
-1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
6<br>
0 0-1 0.00000000<br>
-1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
7<br>
0 0-1 0.00000000<br>
1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
8<br>
0 1 0 0.00000000<br>
0 0 1 0.00000000<br>
1 0 0 0.00000000<br>
9<br>
0-1 0 0.00000000<br>
0 0 1 0.00000000<br>
-1 0 0 0.00000000<br>
10<br>
0 1 0 0.00000000<br>
0 0-1 0.00000000<br>
-1 0 0 0.00000000<br>
11<br>
0-1 0 0.00000000<br>
0 0-1 0.00000000<br>
1 0 0 0.00000000<br>
12<br>
0 1 0 0.00000000<br>
1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
13<br>
0-1 0 0.00000000<br>
-1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
14<br>
0 1 0 0.00000000<br>
-1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
15<br>
0-1 0 0.00000000<br>
1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
16<br>
1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
0-1 0 0.00000000<br>
17<br>
-1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
0 1 0 0.00000000<br>
18<br>
-1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
0-1 0 0.00000000<br>
19<br>
1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
0 1 0 0.00000000<br>
20<br>
0 0 1 0.00000000<br>
0 1 0 0.00000000<br>
-1 0 0 0.00000000<br>
21<br>
0 0 1 0.00000000<br>
0-1 0 0.00000000<br>
1 0 0 0.00000000<br>
22<br>
0 0-1 0.00000000<br>
0 1 0 0.00000000<br>
1 0 0 0.00000000<br>
23<br>
0 0-1 0.00000000<br>
0-1 0 0.00000000<br>
-1 0 0 0.00000000<br>
24<br>
-1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
0 0-1 0.00000000<br>
25<br>
1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
0 0-1 0.00000000<br>
26<br>
1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
0 0 1 0.00000000<br>
27<br>
-1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
0 0 1 0.00000000<br>
28<br>
0 0-1 0.00000000<br>
-1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
29<br>
0 0-1 0.00000000<br>
1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
30<br>
0 0 1 0.00000000<br>
1 0 0 0.00000000<br>
0-1 0 0.00000000<br>
31<br>
0 0 1 0.00000000<br>
-1 0 0 0.00000000<br>
0 1 0 0.00000000<br>
32<br>
0-1 0 0.00000000<br>
0 0-1 0.00000000<br>
-1 0 0 0.00000000<br>
33<br>
0 1 0 0.00000000<br>
0 0-1 0.00000000<br>
1 0 0 0.00000000<br>
34<br>
0-1 0 0.00000000<br>
0 0 1 0.00000000<br>
1 0 0 0.00000000<br>
35<br>
0 1 0 0.00000000<br>
0 0 1 0.00000000<br>
-1 0 0 0.00000000<br>
36<br>
0-1 0 0.00000000<br>
-1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
37<br>
0 1 0 0.00000000<br>
1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
38<br>
0-1 0 0.00000000<br>
1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
39<br>
0 1 0 0.00000000<br>
-1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
40<br>
-1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
0 1 0 0.00000000<br>
41<br>
1 0 0 0.00000000<br>
0 0-1 0.00000000<br>
0-1 0 0.00000000<br>
42<br>
1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
0 1 0 0.00000000<br>
43<br>
-1 0 0 0.00000000<br>
0 0 1 0.00000000<br>
0-1 0 0.00000000<br>
44<br>
0 0-1 0.00000000<br>
0-1 0 0.00000000<br>
1 0 0 0.00000000<br>
45<br>
0 0-1 0.00000000<br>
0 1 0 0.00000000<br>
-1 0 0 0.00000000<br>
46<br>
0 0 1 0.00000000<br>
0-1 0 0.00000000<br>
-1 0 0 0.00000000<br>
47<br>
0 0 1 0.00000000<br>
0 1 0 0.00000000<br>
1 0 0 0.00000000<br>
48<br>
</div>
<div><br>
</div>
<div>then I do step by step</div>
<div>1. init_lapw -b</div>
<div>2. run_lapw -in1new 3 # I use -in1new 3 to avoid the QTL-B value warning message in the last few cycles of case.scf file<br>
</div>
<div>3. using xcrysden to generate a k path along GAMMA-W-X-L with 400 k points.<br>
since the klist_band file is too long. I share it on https://pastebin.com/ZaYuFMZE</div>
<div>4. x lapw1 -band</div>
<div>5. x lapw2 -band -qtl</div>
<div><br>
</div>
<div>finally, I use the data in case.qtl to plot bands<br>
</div>
<div>in [-10eV,10eV] range, it looks pretty normal as shared in below link</div>
<div>https://pasteboard.co/JKPC1tB.png</div>
<div>in [-2eV,-1eV] zoom in range, the look of bands becomes abnormal with full of sawtooth bump as shared in link</div>
<div>https://pasteboard.co/JKPCB7Y.png</div>
<div><br>
</div>
<div>So I am wondering if this is a bug? Or what I have done wrong to have this kind of bands(it appears in all my other bands calculation)? I inspected the k path and found it is pretty fine. So I can not think of a reason why the eigenvalue solutions would
be discontinous at two nearby k points.<br>
</div>
<div><br>
</div>
<div>best regards<br>
</div>
<div><br>
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