<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap:break-word"><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px;color:rgba(0,0,0,1.0);margin:0px;line-height:auto">Dear all,</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px;color:rgba(0,0,0,1.0);margin:0px;line-height:auto"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px;color:rgba(0,0,0,1.0);margin:0px;line-height:auto">Thanks for your quick apply and you are really helpful. I’m new to quantum espresso and make such a mistake.</div> <div><br></div>Best,<div>Tiangang<br> <div id="bloop_sign_1553416482292820992" class="bloop_sign"></div> <br><p class="airmail_on">On March 24, 2019 at 3:57:17 PM, Ari P Seitsonen (<a href="mailto:ari.p.seitsonen@iki.fi">ari.p.seitsonen@iki.fi</a>) wrote:</p> <blockquote type="cite" class="clean_bq"><span><div><div></div><div>
<br>Dar Tiagang,
<br>
<br> I guess that the value 'celldm(3)= 10.431292329' should actually be
<br>1.46419098375312488028, as it is interpreted as c/a, not simply c. If you
<br>use the variables 'a' and 'c' in the input they are the absolute lengths
<br>of the cell vectors and in Ångström. Just my guess...
<br>
<br> Greetings from Paris,
<br>
<br> apsi
<br>
<br>-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
<br> Ari Paavo Seitsonen / <a href="mailto:Ari.P.Seitsonen@iki.fi">Ari.P.Seitsonen@iki.fi</a> / <a href="http://www.iki.fi/~apsi/">http://www.iki.fi/~apsi/</a>
<br> Ecole Normale Supérieure (ENS), Département de Chimie, Paris
<br> Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935
<br>
<br>
<br>On Sat, 23 Mar 2019, Tiangang Zhou wrote:
<br>
<br>>
<br>> Hello all,
<br>>
<br>> I'm working on the beta-FeSe system. In the first step I have done a simple LDA calculation. Unfortunately, after
<br>> adjusting ecutwfc and scf K_POINTS, I can’t get the relatively accurate result compared to VASP and wien2k (the
<br>> result of VASP and wien2k agree well on the fermi surface). It’s likely that the pseudopotential has some problem
<br>> or I miss some key steps. The input files are listed below.
<br>>
<br>> <a href="http://fe_se.scf.in">fe_se.scf.in</a>
<br>> ```
<br>> &control
<br>> calculation = 'scf'
<br>> restart_mode='from_scratch',
<br>> prefix='fe_se',
<br>> pseudo_dir = '/home/tgzhou/softwares/qe_release_6.4/pseudo/',
<br>> outdir='tempdir/'
<br>> /
<br>> &system
<br>> ibrav= 6, celldm(1)= 7.124270293115536, celldm(3)= 10.431292329,
<br>> nat= 4, ntyp= 2,
<br>> ecutwfc = 120.0,
<br>> localization_thr = 0.01,
<br>> occupations='smearing', smearing='mp', degauss=0.02
<br>> /
<br>> &electrons
<br>> mixing_beta = 0.7,
<br>> conv_thr = 1.0d-10
<br>> /
<br>> ATOMIC_SPECIES
<br>> Fe 55.845 Fe.pz-n-kjpaw_psl.1.0.0.UPF
<br>> Se 78.96 Se.pz-n-kjpaw_psl.1.0.0.UPF
<br>> ATOMIC_POSITIONS crystal
<br>> Fe 0.000000000 0.000000000 0.000000000
<br>> Fe 0.500000000 0.500000000 0.000000000
<br>> Se 0.000000000 0.500000000 0.768115942
<br>> Se 0.500000000 0.000000000 0.231884057
<br>> K_POINTS automatic
<br>> 8 8 4 0 0 0
<br>> ```
<br>>
<br>> <a href="http://fe_se.band.in">fe_se.band.in</a>
<br>> ```
<br>> &control
<br>> calculation='bands'
<br>> pseudo_dir = '/home/tgzhou/softwares/qe_release_6.4/pseudo/',
<br>> outdir='tempdir/',
<br>> prefix='fe_se'
<br>> /
<br>> &system
<br>> ibrav= 6, celldm(1)= 7.124270293115536, celldm(3)= 10.431292329,
<br>> nat= 4, ntyp= 2,
<br>> ecutwfc = 120.0,
<br>> nbnd=20
<br>> /
<br>> &electrons
<br>> /
<br>> ATOMIC_SPECIES
<br>> Fe 55.845 Fe.pz-n-kjpaw_psl.1.0.0.UPF
<br>> Se 78.96 Se.pz-n-kjpaw_psl.1.0.0.UPF
<br>> ATOMIC_POSITIONS crystal
<br>> Fe 0.000000000 0.000000000 0.000000000
<br>> Fe 0.500000000 0.500000000 0.000000000
<br>> Se 0.000000000 0.500000000 0.768115942
<br>> Se 0.500000000 0.000000000 0.231884057
<br>> K_POINTS crystal_b
<br>> 4
<br>> 0.0 0.0 0.0 50
<br>> 0.5 0.0 0.0 50
<br>> 0.5 0.5 0.0 50
<br>> 0.0 0.0 0.0 1
<br>> ```
<br>>
<br>>
<br>> The band structure is in the path \Gamma-X-M-\Gamma. And those two have some similarity but the qe FeSe band are
<br>> much more narrow.
<br>>
<br>> qe FeSe band structure <a href="https://drive.google.com/file/d/1wG1Nm-f5v03-kfefJoPZ4gSD4rYaJSQa/view">https://drive.google.com/file/d/1wG1Nm-f5v03-kfefJoPZ4gSD4rYaJSQa/view</a>
<br>> vasp FeSe band structure <a href="https://drive.google.com/file/d/1T0iNg7oecpey2dD6BB9iNrvjS6rm7Mnr/view">https://drive.google.com/file/d/1T0iNg7oecpey2dD6BB9iNrvjS6rm7Mnr/view</a>
<br>>
<br>>
<br>> Best,
<br>>
<br>> Tiangang Zhou
<br>> School of Physics
<br>> Peking University
<br>>
<br>>
<br>>_______________________________________________
<br>users mailing list
<br><a href="mailto:users@lists.quantum-espresso.org">users@lists.quantum-espresso.org</a>
<br><a href="https://lists.quantum-espresso.org/mailman/listinfo/users">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div></div></span></blockquote></div></body></html>