<div dir="ltr"><div class="gmail_default" style="font-size:small">Dear users,</div><div class="gmail_default" style="font-size:small"><br></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></div><div class="gmail_default" style="font-size:small">a) Bowen Zeng et al 2018 J. Phys. D: Appl. Phys. 51 235302;<br></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></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></div><div class="gmail_default" style="font-size:small"><br></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></div><div class="gmail_default" style="font-size:small">A) SCF</div><div class="gmail_default" style="font-size:small">&control<br>    prefix='gep',<br>    calculation='scf'<br>    nstep=0<br>    tstress=.false.<br>    tprnfor= .true.<br>    etot_conv_thr = 1.0D-5<br>    forc_conv_thr = 1.0D-7<br>    pseudo_dir = '/home/malbuquerque/pseudos/',<br>    outdir='./'<br> /<br> &system<br>    ibrav=  4,<br>a=  6.982664008,<br>c = 16.000000000,<br>nat= 8,<br> ntyp= 2,<br>ecutwfc = 120,<br> nbnd = 40<br>       vdw_corr='grimme-d2'<br>        occupations='fixed',<br>/<br>&electrons<br>electron_maxstep = 400<br>conv_thr = 1.0d-12<br>diagonalization='david'<br>mixing_mode='plain'<br>mixing_beta= 0.7<br> /<br>&ions<br>ion_dynamics='bfgs'<br>/<br>&CELL<br>  cell_dynamics = 'bfgs',<br>   press_conv_thr = 0.5,<br>   cell_factor = 2.0,<br>   cell_dofree = '2Dxy',<br>/<br>ATOMIC_SPECIES<br>Ge  72.640   Ge.pbe-hgh.UPF<br>P   30.974   P.pbe-hgh.UPF<br>ATOMIC_POSITIONS crystal<br>Ge       0.836927687   0.360474777   0.413486925<br>Ge       0.503586578   0.693798663   0.359352022<br>P        0.325445130   0.871903831   0.425075713<br>P        0.859830506   0.871910609   0.425081984<br>P        0.325454709   0.337550097   0.425072126<br>P        0.014988446   0.182362365   0.347653353<br>P        0.014997809   0.716639703   0.347643675<br>P        0.480752135   0.182372957   0.347659202<br>K_POINTS automatic<br>13 13 1 0 0 0<br></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">B) BANDS</div><div class="gmail_default" style="font-size:small">&control<br>    prefix='gep',<br>    calculation='bands'<br>    nstep=0<br>    tstress=.false.<br>    tprnfor= .true.<br>    etot_conv_thr = 1.0D-5<br>    forc_conv_thr = 1.0D-7<br>    pseudo_dir = '/home/malbuquerque/pseudos/',<br>    outdir='./'<br> /<br>&system<br>ibrav=  4,<br>a=  6.982664008,<br>c = 16.000000000,<br>nat= 8,<br> ntyp= 2,<br>ecutwfc = 120,<br> nbnd = 40<br>       vdw_corr='grimme-d2'<br>        occupations='fixed',<br> /<br> &electrons<br>electron_maxstep = 400<br>conv_thr = 1.0d-12<br>diagonalization='david'<br>mixing_mode='plain'<br>mixing_beta= 0.7<br> /<br>&ions<br>ion_dynamics='bfgs'<br>/<br>&CELL<br>  cell_dynamics = 'bfgs',<br>   press_conv_thr = 0.5,<br>   cell_factor = 2.0,<br>   cell_dofree = '2Dxy',<br>/<br>ATOMIC_SPECIES<br>Ge  72.640   Ge.pbe-hgh.UPF<br>P   30.974   P.pbe-hgh.UPF<br>ATOMIC_POSITIONS (crystal)<br>Ge       0.836927687   0.360474777   0.413486925<br>Ge       0.503586578   0.693798663   0.359352022<br>P        0.325445130   0.871903831   0.425075713<br>P        0.859830506   0.871910609   0.425081984<br>P        0.325454709   0.337550097   0.425072126<br>P        0.014988446   0.182362365   0.347653353<br>P        0.014997809   0.716639703   0.347643675<br>P        0.480752135   0.182372957   0.347659202<br>K_POINTS crystal_b<br>4<br>0.000000000    0.000000000    0.000000000  30 !! Gamma<br>0.333333333    0.333333333    0.000000000  30 !! K<br>0.500000000    0.000000000    0.000000000  30 !! M<br>0.000000000    0.000000000    0.000000000  30 !! Gamma<br></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"><br></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></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></div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">With all the best regards,</div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote><span style="text-align:center;color:rgb(0,0,0)"><div style="text-align:left"><span style="font-style:italic"><span style="font-style:normal"><font face="times new roman, serif">Marcelo Albuquerque</font></span></span></div></span><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote><span style="text-align:center;color:rgb(0,0,0)"><div style="text-align:left"><font face="times new roman, serif">Ph.D. Candidate</font></div></span><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote><span style="text-align:center;color:rgb(0,0,0)"><div style="text-align:left"><font face="times new roman, serif">Institute of </font><span style="font-family:"times new roman",serif">Physics</span></div></span><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote><span style="color:rgb(0,0,0);text-align:center"><div style="text-align:left"><font face="times new roman, serif">Fluminense Federal University</font></div></span><div><div><div style="text-align:left"><font color="#000000" face="times new roman, serif"><span style="background-color:rgb(255,255,255)">Niterói/RJ - Brazil</span></font></div></div></div><div><div dir="ltr"><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"></blockquote></div></div></div></div></div></div>