<div dir="ltr">And I tried with PBE as well not significant difference.<br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">GAUTAM GADDEMANE<div>DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING</div><div>UNIVERSITY OF TEXAS AT DALLAS</div></div></div></div>
<br><div class="gmail_quote">On Thu, Oct 5, 2017 at 4:09 PM, Gautam Gaddemane <span dir="ltr"><<a href="mailto:gautamg88@gmail.com" target="_blank">gautamg88@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div>thank you Dario. When I use VASP I get the exact same result as mentioned in the reference you have atatched but with quantum espresso I get significantly different result especially the band gap. <br></div>If you can have a look at the relax input file I have attached in the email and let met know if I should add anything else ?<div><div class="h5"><br><br> <br>&CONTROL
<br>  calculation='vc-relax',
<br>  outdir='./',
<br>  prefix='calc',
<br>  pseudo_dir='./',
<br>  verbosity='high',
<br>/
<br> <br>&SYSTEM
<br>  ibrav=0,
<br>  celldm(1)= 8.276999830d0
<br>  nat=4,
<br>  ntyp=1,
<br>  ecutwfc=60,
<br>  ecutrho=360,
<br>  input_dft='lda',
<br>  occupations='smearing',
<br>  smearing='mv',
<br>  degauss=0.005d0,
<br>/
<br> <br>&ELECTRONS
<br>  conv_thr=1d-06,
<br>  mixing_beta=0.7d0,
<br>/
<br>&IONS
<br>  ion_dynamics='bfgs'
<br>/
<br> <br>&CELL
<br>  cell_dynamics='bfgs'
<br>  cell_dofree='2Dshape'  
<br>/
<br>ATOMIC_SPECIES
<br>  P 30.973800d0 P.pw-mt_fhi.UPF
<br> <br>ATOMIC_POSITIONS {crystal}
<br> <br> P  0.090000004         0.000000000         0.050195117
<br> P  0.909999967         0.000000000         0.949804902
<br> P  0.590000033         0.500000000         0.949804902
<br> P  0.409999996         0.500000000         0.050195117
<br> <br>K_POINTS {automatic}
<br> <br>  12 12 1 0 0 0
<br> <br>CELL_PARAMETERS {alat}
<br> <br>     1.0000000000000000    0.0000000000000000    0.0000000000000000
<br>     0.0000000000000000    0.7511415530000000    0.0000000000000000
<br>     0.0000000000000000    0.0000000000000000   4.68036529200000000<br><br></div></div></div>thank you<span class="HOEnZb"><font color="#888888"><br></font></span></div><span class="HOEnZb"><font color="#888888">Gautam<br><div><div><div><br></div></div></div></font></span></div><div class="gmail_extra"><div><div class="h5"><br clear="all"><div><div class="m_-3099649323113371671gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">GAUTAM GADDEMANE<div>DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING</div><div>UNIVERSITY OF TEXAS AT DALLAS</div></div></div></div>
<br></div></div><div><div class="h5"><div class="gmail_quote">On Thu, Oct 5, 2017 at 3:54 PM, dario rocca <span dir="ltr"><<a href="mailto:roccad@gmail.com" target="_blank">roccad@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear Gautam,<div>The values you get are not completely impossible.<br><div>Try with PBE, since there are for sure a couple of calculations in the literature to compare with.</div></div><div>For example</div><div><a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.085402" target="_blank">https://journals.aps.org/prb/a<wbr>bstract/10.1103/PhysRevB.90.08<wbr>5402</a><br></div><div>Best,</div><div>Dario</div></div><div class="m_-3099649323113371671HOEnZb"><div class="m_-3099649323113371671h5"><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Oct 5, 2017 at 10:31 PM, Gautam Gaddemane <span dir="ltr"><<a href="mailto:gautamg88@gmail.com" target="_blank">gautamg88@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">4.45 A and 3.26 A and a band gap of 0.67eV.</div><div class="gmail_extra"><span><br clear="all"><div><div class="m_-3099649323113371671m_425397436961710348m_6787477276787962591gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">GAUTAM GADDEMANE<div>DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING</div><div>UNIVERSITY OF TEXAS AT DALLAS</div></div></div></div>
<br></span><div><div class="m_-3099649323113371671m_425397436961710348h5"><div class="gmail_quote">On Thu, Oct 5, 2017 at 3:28 PM, Matthieu Fortin-Deschênes <span dir="ltr"><<a href="mailto:matthieu.fortin-deschenes@polymtl.ca" target="_blank">matthieu.fortin-deschenes@pol<wbr>ymtl.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">What values of lattice parameters and band gap did you get? With LDA<br>
you expect some differences compared to experimental values.<br>
<br>
Matthieu<br>
<br>
Gautam Gaddemane <<a href="mailto:gautamg88@gmail.com" target="_blank">gautamg88@gmail.com</a>> a Ã©crit :<br>
<div><div class="m_-3099649323113371671m_425397436961710348m_6787477276787962591h5"><br>
> Dear All,<br>
><br>
> I am trying to calculate the bands tructure for monolayer phosphorene and I<br>
> am just a week old in using quantum espresso.<br>
>> From the bulk unit cell I prepared an input file to relax the structure but<br>
> I was not able to get a good lattice constant nor a good band gap. It would<br>
> be very helpful if someone would guide me in this procedure.<br>
> I have attahced the file I used to relax in this email<br>
><br>
><br>
> &CONTROL<br>
>  Â calculation='vc-relax',<br>
>  Â outdir='./',<br>
>  Â prefix='calc',<br>
>  Â pseudo_dir='./',<br>
>  Â verbosity='high',<br>
> /<br>
><br>
> &SYSTEM<br>
>  Â ibrav=0,<br>
>  Â celldm(1)= 8.276999830d0<br>
>  Â nat=4,<br>
>  Â ntyp=1,<br>
>  Â ecutwfc=60,<br>
>  Â ecutrho=360,<br>
>  Â input_dft='lda',<br>
>  Â occupations='smearing',<br>
>  Â smearing='mv',<br>
>  Â degauss=0.005d0,<br>
> /<br>
><br>
> &ELECTRONS<br>
>  Â conv_thr=1d-06,<br>
>  Â mixing_beta=0.7d0,<br>
> /<br>
> &IONS<br>
>  Â ion_dynamics='bfgs'<br>
> /<br>
><br>
> &CELL<br>
>  Â cell_dynamics='bfgs'<br>
>  Â cell_dofree='2Dshape'<br>
> /<br>
> ATOMIC_SPECIES<br>
>  Â P 30.973800d0 P.pw-mt_fhi.UPF<br>
><br>
> ATOMIC_POSITIONS {crystal}<br>
><br>
>  P  0.090000004  Â  Â  Â  Â 0.000000000  Â  Â  Â  Â 0.050195117<br>
>  P  0.909999967  Â  Â  Â  Â 0.000000000  Â  Â  Â  Â 0.949804902<br>
>  P  0.590000033  Â  Â  Â  Â 0.500000000  Â  Â  Â  Â 0.949804902<br>
>  P  0.409999996  Â  Â  Â  Â 0.500000000  Â  Â  Â  Â 0.050195117<br>
><br>
> K_POINTS {automatic}<br>
><br>
>  Â 12 12 1 0 0 0<br>
><br>
> CELL_PARAMETERS {alat}<br>
><br>
>  Â  Â  1.0000000000000000  Â  0.0000000000000000  Â  0.0000000000000000<br>
>  Â  Â  0.0000000000000000  Â  0.7511415530000000  Â  0.0000000000000000<br>
>  Â  Â  0.0000000000000000  Â  0.0000000000000000  Â 4.68036529200000000<br>
><br>
><br>
> thank you<br>
> Gautam<br>
><br>
> GAUTAM GADDEMANE<br>
> DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING<br>
> UNIVERSITY OF TEXAS AT DALLAS<br>
<br>
<br>
<br>
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