<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi Marcelo,<div class=""><br class=""></div><div class="">I do not see an evident reason why you should find a discrepancy. However, by looking to Fig. 1b of the first reference and to the side view of you structure (as obtained by opening the scf input directly with XcrysDEN), it seems to me that there is some difference in the z coordinates. Also, I tried (but I don’t know if in the correct way) to calculate "the puckered height between P–P and Ge–Ge” as mentioned in the reference. Again, your structure seems to be different. Did you relax the structure before making the scf? What is the value of “Total force” at the end of the scp output?</div><div class=""><br class=""></div><div class="">Giovanni</div><div class=""><br class=""></div><div class="">PS is there any reason why not trying with PAW pseudo potentials requiring a much smaller cutoff?</div><div class="">(this has of course nothing to do with your issue)<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 20 Jul 2021, at 17:42, Marcelo Albuquerque <<a href="mailto:marcelofilho@id.uff.br" class="">marcelofilho@id.uff.br</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_default" style="font-size:small">Dear users,</div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">I'm trying to calculate the electronic band structure of GeP3, but I haven't been able to reproduce it, as shown in both references below. </div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">a) Bowen Zeng et al 2018 J. Phys. D: Appl. Phys. 51 235302;<br class=""></div><div class="gmail_default" style="font-size:small">b) Yu Jing, et al, Nano Lett. 2017, 17, 3, 1833–1838.</div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">BTW, they were computed using VASP code, and I don't understand why I'm facing such an issue. I have already tried many different approaches to calculate this band structure, but it simply doesn't work.<br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">Here follows the inputs I used for the scf and the bands calculations. </div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">A) SCF</div><div class="gmail_default" style="font-size:small">&control<br class=""> prefix='gep',<br class=""> calculation='scf'<br class=""> nstep=0<br class=""> tstress=.false.<br class=""> tprnfor= .true.<br class=""> etot_conv_thr = 1.0D-5<br class=""> forc_conv_thr = 1.0D-7<br class=""> pseudo_dir = '/home/malbuquerque/pseudos/',<br class=""> outdir='./'<br class=""> /<br class=""> &system<br class=""> ibrav= 4,<br class="">a= 6.982664008,<br class="">c = 16.000000000,<br class="">nat= 8,<br class=""> ntyp= 2,<br class="">ecutwfc = 120,<br class=""> nbnd = 40<br class=""> vdw_corr='grimme-d2'<br class=""> occupations='fixed',<br class="">/<br class="">&electrons<br class="">electron_maxstep = 400<br class="">conv_thr = 1.0d-12<br class="">diagonalization='david'<br class="">mixing_mode='plain'<br class="">mixing_beta= 0.7<br class=""> /<br class="">&ions<br class="">ion_dynamics='bfgs'<br class="">/<br class="">&CELL<br class=""> cell_dynamics = 'bfgs',<br class=""> press_conv_thr = 0.5,<br class=""> cell_factor = 2.0,<br class=""> cell_dofree = '2Dxy',<br class="">/<br class="">ATOMIC_SPECIES<br class="">Ge 72.640 Ge.pbe-hgh.UPF<br class="">P 30.974 P.pbe-hgh.UPF<br class="">ATOMIC_POSITIONS crystal<br class="">Ge 0.836927687 0.360474777 0.413486925<br class="">Ge 0.503586578 0.693798663 0.359352022<br class="">P 0.325445130 0.871903831 0.425075713<br class="">P 0.859830506 0.871910609 0.425081984<br class="">P 0.325454709 0.337550097 0.425072126<br class="">P 0.014988446 0.182362365 0.347653353<br class="">P 0.014997809 0.716639703 0.347643675<br class="">P 0.480752135 0.182372957 0.347659202<br class="">K_POINTS automatic<br class="">13 13 1 0 0 0<br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">B) BANDS</div><div class="gmail_default" style="font-size:small">&control<br class=""> prefix='gep',<br class=""> calculation='bands'<br class=""> nstep=0<br class=""> tstress=.false.<br class=""> tprnfor= .true.<br class=""> etot_conv_thr = 1.0D-5<br class=""> forc_conv_thr = 1.0D-7<br class=""> pseudo_dir = '/home/malbuquerque/pseudos/',<br class=""> outdir='./'<br class=""> /<br class="">&system<br class="">ibrav= 4,<br class="">a= 6.982664008,<br class="">c = 16.000000000,<br class="">nat= 8,<br class=""> ntyp= 2,<br class="">ecutwfc = 120,<br class=""> nbnd = 40<br class=""> vdw_corr='grimme-d2'<br class=""> occupations='fixed',<br class=""> /<br class=""> &electrons<br class="">electron_maxstep = 400<br class="">conv_thr = 1.0d-12<br class="">diagonalization='david'<br class="">mixing_mode='plain'<br class="">mixing_beta= 0.7<br class=""> /<br class="">&ions<br class="">ion_dynamics='bfgs'<br class="">/<br class="">&CELL<br class=""> cell_dynamics = 'bfgs',<br class=""> press_conv_thr = 0.5,<br class=""> cell_factor = 2.0,<br class=""> cell_dofree = '2Dxy',<br class="">/<br class="">ATOMIC_SPECIES<br class="">Ge 72.640 Ge.pbe-hgh.UPF<br class="">P 30.974 P.pbe-hgh.UPF<br class="">ATOMIC_POSITIONS (crystal)<br class="">Ge 0.836927687 0.360474777 0.413486925<br class="">Ge 0.503586578 0.693798663 0.359352022<br class="">P 0.325445130 0.871903831 0.425075713<br class="">P 0.859830506 0.871910609 0.425081984<br class="">P 0.325454709 0.337550097 0.425072126<br class="">P 0.014988446 0.182362365 0.347653353<br class="">P 0.014997809 0.716639703 0.347643675<br class="">P 0.480752135 0.182372957 0.347659202<br class="">K_POINTS crystal_b<br class="">4<br class="">0.000000000 0.000000000 0.000000000 30 !! Gamma<br class="">0.333333333 0.333333333 0.000000000 30 !! K<br class="">0.500000000 0.000000000 0.000000000 30 !! M<br class="">0.000000000 0.000000000 0.000000000 30 !! Gamma<br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">In fact, I used the the QE versions6.7, 6.6 and 6.4.1, which gave me the same strange result. I'm also sending a PNG file showing the obtained bands. The red line is the VBM, and the blue one is the CBM (or it was supposed to be). What is weird is that I was expecting (according to the aforementioned reference) that the blue band was located a little bit above where it is in this figure. Also the orange one should be a little bit above, close to the VBM.</div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">Could anyone help me or give me some advice about this problem. I really appreciate it in advance.</div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small"><br class=""></div><div class="gmail_default" style="font-size:small">With all the best regards,</div><div class=""><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr" class=""><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote><span style="text-align: center;" class=""><div style="text-align:left" class=""><span style="font-style:italic" class=""><span style="font-style:normal" class=""><font face="times new roman, serif" class="">Marcelo Albuquerque</font></span></span></div></span><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote><span style="text-align: center;" class=""><div style="text-align:left" class=""><font face="times new roman, serif" class="">Ph.D. Candidate</font></div></span><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote><span style="text-align: center;" class=""><div style="text-align:left" class=""><font face="times new roman, serif" class="">Institute of </font><span style="font-family:"times new roman",serif" class="">Physics</span></div></span><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote><span style="text-align: center;" class=""><div style="text-align:left" class=""><font face="times new roman, serif" class="">Fluminense Federal University</font></div></span><div class=""><div class=""><div style="text-align:left" class=""><font face="times new roman, serif" class=""><span style="background-color:rgb(255,255,255)" class="">Niterói/RJ - Brazil</span></font></div></div></div><div class=""><div dir="ltr" class=""><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px" class=""></blockquote></div></div></div></div></div></div>
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