And I tried with PBE as well not significant difference. GAUTAM GADDEMANE DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING UNIVERSITY OF TEXAS AT DALLAS
On Thu, Oct 5, 2017 at 4:09 PM, Gautam Gaddemane <gautam...@gmail.com> wrote: > 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. > 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 ? > > > > &CONTROL > calculation='vc-relax', > outdir='./', > prefix='calc', > pseudo_dir='./', > verbosity='high', > / > > &SYSTEM > ibrav=0, > celldm(1)= 8.276999830d0 > nat=4, > ntyp=1, > ecutwfc=60, > ecutrho=360, > input_dft='lda', > occupations='smearing', > smearing='mv', > degauss=0.005d0, > / > > &ELECTRONS > conv_thr=1d-06, > mixing_beta=0.7d0, > / > &IONS > ion_dynamics='bfgs' > / > > &CELL > cell_dynamics='bfgs' > cell_dofree='2Dshape' > / > ATOMIC_SPECIES > P 30.973800d0 P.pw-mt_fhi.UPF > > ATOMIC_POSITIONS {crystal} > > P 0.090000004 0.000000000 0.050195117 > P 0.909999967 0.000000000 0.949804902 > P 0.590000033 0.500000000 0.949804902 > P 0.409999996 0.500000000 0.050195117 > > K_POINTS {automatic} > > 12 12 1 0 0 0 > > CELL_PARAMETERS {alat} > > 1.0000000000000000 0.0000000000000000 0.0000000000000000 > 0.0000000000000000 0.7511415530000000 0.0000000000000000 > 0.0000000000000000 0.0000000000000000 4.68036529200000000 > > thank you > Gautam > > > GAUTAM GADDEMANE > DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING > UNIVERSITY OF TEXAS AT DALLAS > > On Thu, Oct 5, 2017 at 3:54 PM, dario rocca <roc...@gmail.com> wrote: > >> Dear Gautam, >> The values you get are not completely impossible. >> Try with PBE, since there are for sure a couple of calculations in the >> literature to compare with. >> For example >> https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.085402 >> Best, >> Dario >> >> On Thu, Oct 5, 2017 at 10:31 PM, Gautam Gaddemane <gautam...@gmail.com> >> wrote: >> >>> 4.45 A and 3.26 A and a band gap of 0.67eV. >>> >>> GAUTAM GADDEMANE >>> DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING >>> UNIVERSITY OF TEXAS AT DALLAS >>> >>> On Thu, Oct 5, 2017 at 3:28 PM, Matthieu Fortin-Deschênes < >>> matthieu.fortin-desche...@polymtl.ca> wrote: >>> >>>> What values of lattice parameters and band gap did you get? With LDA >>>> you expect some differences compared to experimental values. >>>> >>>> Matthieu >>>> >>>> Gautam Gaddemane <gautam...@gmail.com> a écrit : >>>> >>>> > Dear All, >>>> > >>>> > I am trying to calculate the bands tructure for monolayer phosphorene >>>> and I >>>> > am just a week old in using quantum espresso. >>>> >> From the bulk unit cell I prepared an input file to relax the >>>> structure but >>>> > I was not able to get a good lattice constant nor a good band gap. It >>>> would >>>> > be very helpful if someone would guide me in this procedure. >>>> > I have attahced the file I used to relax in this email >>>> > >>>> > >>>> > &CONTROL >>>> > calculation='vc-relax', >>>> > outdir='./', >>>> > prefix='calc', >>>> > pseudo_dir='./', >>>> > verbosity='high', >>>> > / >>>> > >>>> > &SYSTEM >>>> > ibrav=0, >>>> > celldm(1)= 8.276999830d0 >>>> > nat=4, >>>> > ntyp=1, >>>> > ecutwfc=60, >>>> > ecutrho=360, >>>> > input_dft='lda', >>>> > occupations='smearing', >>>> > smearing='mv', >>>> > degauss=0.005d0, >>>> > / >>>> > >>>> > &ELECTRONS >>>> > conv_thr=1d-06, >>>> > mixing_beta=0.7d0, >>>> > / >>>> > &IONS >>>> > ion_dynamics='bfgs' >>>> > / >>>> > >>>> > &CELL >>>> > cell_dynamics='bfgs' >>>> > cell_dofree='2Dshape' >>>> > / >>>> > ATOMIC_SPECIES >>>> > P 30.973800d0 P.pw-mt_fhi.UPF >>>> > >>>> > ATOMIC_POSITIONS {crystal} >>>> > >>>> > P 0.090000004 0.000000000 0.050195117 >>>> > P 0.909999967 0.000000000 0.949804902 >>>> > P 0.590000033 0.500000000 0.949804902 >>>> > P 0.409999996 0.500000000 0.050195117 >>>> > >>>> > K_POINTS {automatic} >>>> > >>>> > 12 12 1 0 0 0 >>>> > >>>> > CELL_PARAMETERS {alat} >>>> > >>>> > 1.0000000000000000 0.0000000000000000 0.0000000000000000 >>>> > 0.0000000000000000 0.7511415530000000 0.0000000000000000 >>>> > 0.0000000000000000 0.0000000000000000 4.68036529200000000 >>>> > >>>> > >>>> > thank you >>>> > Gautam >>>> > >>>> > GAUTAM GADDEMANE >>>> > DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING >>>> > UNIVERSITY OF TEXAS AT DALLAS >>>> >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> Pw_forum@pwscf.org >>>> http://pwscf.org/mailman/listinfo/pw_forum >>> >>> >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> Pw_forum@pwscf.org >>> http://pwscf.org/mailman/listinfo/pw_forum >>> >> >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum@pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum >> > >
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