You have specified the q-points in crystal fractionary units, hence you have to specify q_in_cryst_coord=.true. This can be safely used in conjunction with q_in_band_form, which is a completely unrelated option.
Also: You way of specifying the cell parameters is discouraged and may cause problems with symmetry detection, but it should work. Using a k-points grid that includes the K point can be a source of troubles, I would recommend using 16x16x1 or even 32x32x1 for better results. hth -- Lorenzo Paulatto - Paris On Mar 30 2021, at 4:19 pm, Evgenii <eisyso...@stud.eltech.ru> wrote: > Dear Quantum Espresso experts, > > I am having trouble calculating the phonon bands of graphene. > > First, I took the cif-file of the already relaxed graphite cell from the > Materials Project site https://next-gen.materialsproject.org/ and made > graphene cell from it by hand. > Then I relaxed the cell obtained with vc-relax and 12x12x1 k-point set. > I used the same parameters to perform a scf calculation: > > &CONTROL > calculation='scf' > title='graphene' > prefix='graphene' > verbosity='high' > restart_mode='from_scratch' > nstep=1000 > iprint=1 > tstress=.true. > tprnfor=.true. > disk_io='default' > pseudo_dir = '/home/mxm2/Desktop/Graphene', > outdir='/home/mxm2/Desktop/Graphene/temp' > / > &SYSTEM > ibrav = 0, > celldm(1)=1.889726, > nat = 2, > ntyp = 1, > ecutwfc = 60.0 , > ecutrho = 480.0 , > / > &ELECTRONS > electron_maxstep = 1000, > conv_thr = 1.0d-12 , > mixing_mode = 'plain' , > mixing_beta = 0.7d0 , > / > ATOMIC_SPECIES > C 12.011 C.pz-rrkjus.UPF > ATOMIC_POSITIONS (crystal) > C 0.000000000 0.000000000 0.000861580 > C 0.333333000 0.666667000 0.000838420 > CELL_PARAMETERS (alat) > 2.438515837 -0.000000000 0.000000000 > -1.219257919 2.111816662 0.000000000 > -0.000000000 -0.000000000 19.995916314 > > K_POINTS automatic > 12 12 1 0 0 0 > > Then, I run ph.in calculation: > > &inputph > recover=.true. > tr2_ph=1.0d-14, > prefix='graphene', > ldisp=.true. > nq1=12, > nq2=12, > nq3=1, > amass(1)=12.011, > outdir='/home/mxm2/Desktop/Graphene/temp', > fildyn='graphene.dyn', > / > > My q2r: > > &input > fildyn='graphene.dyn', > zasr='simple', > flfrc='graphene.12x12x1.fc' > / > > Matdyn input: > > &input > asr='simple', > amass(1)=12.011, > flfrc='graphene.12x12x1.fc', > flfrq='graphene.disp.freq' > q_in_band_form=.true., > / > 4 ! number of q-points > 0.000 0.000 0.000 10 ! gamma point > 0.500 0.000 0.000 10 ! M > 0.333 0.333 0.000 10 ! K > 0.000 0.000 0.000 1 ! gamma point > > Plotband: > > graphene.disp.freq > 0 1600 > graphene.disp.freq.dat > graphene.disp.freq.ps > 0 > 100 0 > > Why the phonon dispersion does not match the pictures from the papers and for > calculations with e.g. 18x18x1 k-point and nq-point sets the output file of > graphene.dyn1 look like: > > Dielectric Tensor: > > ************************ 166.332153320312 0.000000000000 > 166.332275390625************************ 0.000000000000 > 0.000000000000 0.000000000000 1.116060253916 > > Effective Charges E-U: Z_{alpha}{s,beta} > > atom # 1 > -11117471.575740195811 -0.002632206306 0.000000000000 > -0.002632205375-11117471.579664016142 0.000000000000 > 0.000000000000 0.000000000000 -0.003734609171 > > Also, what is the best way to set the lattice parameters, via Ibrav or > CELL_PARAMETERS? > > Any help is appreciated. > > Best regards, > Evgeniy Sysoev. > > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users
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