Dear Mr. Karpati, Thanks for your reply. I increased nbnd but the results are still the same; the bands are still completely straight (attached below). There is supposed to be a single Dirac point at Γ.
It looks like there is something fundamentally wrong with the input. Do you have any idea what could be the cause of the problem? Are there any special variables I need to use for nanoribbons? Thank you for your help. Larry [image: image.png] On Wed, Aug 5, 2020 at 7:24 AM Tamas Karpati <[email protected]> wrote: > Dear Larry, > > You have almost 300 electrons which means ca. 150 occupied bands, > while you forced QE to use just 2^7. Funny that SCF converged, proves > stability of PWscf :) > > Try to increase nbnd above 150. > > Hope this helps, > t > > > On Wed, Aug 5, 2020 at 3:55 AM Larry Shi <[email protected]> wrote: > >> Dear QE gurus, >> >> I am new to QE and I am currently trying to replicate the band structure >> for a GeI nanoribbon (https://doi.org/10.1103/PhysRevB.89.115429). I >> passivated the Ge atoms with H atoms. When I run the band input file >> (below) after the SCF has been converged, the bands in the resulting band >> structure are all straight lines (they all have constant energy), which is >> absurd. I'm not sure where the issue originates. >> >> Any assistance would be greatly appreciated! >> >> >> &CONTROL >> calculation = "bands" >> max_seconds = 5.18400e+06 >> pseudo_dir = "C:\Users\User\.burai\.pseudopot" >> / >> >> &SYSTEM >> a = 4.62000e+01 >> angle1(1) = 0.00000e+00 >> angle1(2) = 0.00000e+00 >> angle2(1) = 0.00000e+00 >> angle2(2) = 0.00000e+00 >> b = 7.01480e+00 >> c = 3.00000e+01 >> cosab = -5.00000e-01 >> degauss = 1.00000e-02 >> ecutrho = 1.00000e+02 >> ecutwfc = 2.50000e+01 >> ibrav = 8 >> lspinorb = .FALSE. >> nat = 32 >> nbnd = 128 >> nspin = 1 >> ntyp = 3 >> occupations = "smearing" >> smearing = "gaussian" >> starting_magnetization(1) = 0.00000e+00 >> starting_magnetization(2) = 0.00000e+00 >> / >> >> &ELECTRONS >> conv_thr = 1.00000e-07 >> electron_maxstep = 200 >> mixing_beta = 7.00000e-01 >> startingpot = "atomic" >> startingwfc = "atomic+random" >> / >> >> &BANDS >> lsym = .FALSE. >> spin_component = 1 >> / >> >> K_POINTS {tpiba_b} >> 3 >> Z 40 >> gG 40 >> Z 40 >> >> ATOMIC_SPECIES >> Ge 72.61000 Ge.pbe-n-rrkjus_psl.1.0.0.UPF >> I 126.90447 I.pbe-mt_bw.UPF >> H 1.00794 H.pbe-rrkjus.UPF >> >> ATOMIC_POSITIONS {angstrom} >> H -2.005606 1.098069 29.911525 >> Ge 0.019394 2.178887 0.673171 >> Ge 1.988303 1.098069 29.911525 >> I 0.170697 2.062988 3.223532 >> I 2.089141 1.028047 27.356392 >> H -2.005606 5.686290 0.673171 >> Ge -0.036697 4.605472 29.911525 >> I 0.064141 4.535450 27.356392 >> Ge 4.069394 2.178887 0.673171 >> Ge 6.038303 1.098069 29.911525 >> I 4.220697 2.062988 3.223532 >> I 6.139141 1.028047 27.356392 >> Ge 2.044394 5.686290 0.673171 >> Ge 4.013303 4.605472 29.911525 >> I 2.195697 5.570391 3.223532 >> I 4.114141 4.535450 27.356392 >> Ge 8.119394 2.178887 0.673171 >> Ge 10.088303 1.098069 29.911525 >> I 8.270697 2.062988 3.223532 >> I 10.189141 1.028047 27.356392 >> Ge 6.094394 5.686290 0.673171 >> Ge 8.063303 4.605472 29.911525 >> I 6.245697 5.570391 3.223532 >> I 8.164141 4.535450 27.356392 >> Ge 12.169394 2.178887 0.673171 >> H 14.138303 1.098069 29.911525 >> I 12.320697 2.062988 3.223532 >> Ge 10.144394 5.686290 0.673171 >> Ge 12.113303 4.605472 29.911525 >> I 10.295697 5.570391 3.223532 >> I 12.214141 4.535450 27.356392 >> H 14.138303 5.686290 0.673171 >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) >> users mailing list [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
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