In the matdyn.in file, the coordinates of the high-symmetry points should be in cartesian not crystal coordinates since you are using q_in_band_form=.true.
Cheers, Vahid Vahid Askarpour Department of physics and atmospheric science Dalhousie University Halifax, NS CANADA On Jan 22, 2021, at 12:56 PM, Roozbeh Anvari <[email protected]<mailto:[email protected]>> wrote: CAUTION: The Sender of this email is not from within Dalhousie. Dear Quantum Espresso experts, I am having a trouble calculating the phonon bands of graphene at $K$-point, I am using NC+LDA and NC+PBE, ecutwfs=60, Ecutrho=400.0, forc_conv_thr=1.0d-6, as you can see in the attached figure, the calculated acoustic and optical eigenvalues are ok at $\Gamma$ and $M$-points, however the calculated value deviates from what it should be at $K$-point: TA and ZA branches are not overlapping at $K$-point, and a strange bump can be seen when ZO approaches $K$-point, I have checked the convergence for K-mesh, Ecutwfs, and Ecutrho, I have also tried increasing the K and q mesh for scf-calculation, using tr2_ph = 1E-14 and alpha_mix(niter)= .1 also does not improve the results, Thank you for your help, Regards, Roozbeh PDF, physics, Queen's university Here is the setup I am using, step 1, pw.x &CONTROL .... calculation='scf' forc_conv_thr=1.0d-6, / &SYSTEM ibrav=0, nat = 2, ntyp = 1, ecutwfc = 60.0 , ecutrho = 400.0, ! 480 nosym=.true., occupations='smearing', smearing='cold', degauss=0.02 la2F = .true., / &ELECTRONS startingwfc='random' diagonalization='cg' conv_thr = 1.0e-12 mixing_beta = 0.2 electron_maxstep=200 ATOMIC_SPECIES C 12.011 C.pz-vbc.UPF CELL_PARAMETERS (angstrom) 2.428479517 -0.000000605 0.000000000 -1.214240282 2.103124989 0.000000000 0.000000000 0.000000000 20.000000000 ATOMIC_POSITIONS (crystal) C -0.0002315717 0.0002344099 0.4996978700 C 0.6664267343 0.3335704066 0.4996978902 K_POINTS automatic 64 64 1 0 0 0 %-------------------- % step 2 ,pw.x %-------------------- same as above except la2F = .false., K_POINTS automatic 32 32 1 0 0 0 %-------------------- % step 3 , ph.x %-------------------- &inputph tr2_ph=1.0d-14, prefix='ml_gr', fildvscf='ml_gredv', amass(1)=12.011, outdir='./tmp', fildyn='ml_gr.dyn', electron_phonon='interpolated', !el_ph_sigma=0.005, !el_ph_nsigma=10, alpha_mix=0.1 diagonalization='cg', trans=.true., ldisp=.true., nq1=4 , nq2=4, nq3=1 ! nq1=8 , nq2=8, nq3=1 makes no difference / %-------------------- % step 4 , q2r.x %-------------------- &input zasr='simple', fildyn='ml_gr.dyn', flfrc='gr333.fc', la2F=.true. / %-------------------- % step 5 , matdyn.x %-------------------- &input asr='simple', amass(1)=12.011, flfrc='gr333.fc', flfrq='gr333.freq', la2F=.true., dos=.false. q_in_band_form=.true. / 4 0 0 0 20 0 .5 0 20 -0.3333333 0.6666666 0. 20 0 0 0 1 <60_400_64_32_4.png>_______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu<http://www.max-centre.eu>) users mailing list [email protected]<mailto:[email protected]> https://lists.quantum-espresso.org/mailman/listinfo/users
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