Dear Gabriele, I have tried the tefield but i am getting the same messy results again.. The thing is there are no problems in the DOS calculations; only in the band structure. I have increased the E field in the new calculation to 0.1 instead of the 0.001 old value. I am attaching a very small part of the results as a tif file because of the attachment limitations in the forum. When you have time, please let me know what you think... Thank you Elie
Date: Wed, 29 Sep 2010 09:55:03 +0200 From: [email protected] To: pw_forum at pwscf.org Subject: Re: [Pw_forum] Bilayer graphene with an electric field applied Dear Elje, since you are dealing with a slab geometry and you want to apply the field along the direction perpendicular to the surface, why don't you use the sawtooth potential (tefield=.TRUE. instead of lefield=.TRUE.) to generate the E field? On 09/28/2010 10:41 PM, Elie Moujaes wrote: Dear all, I I am trying to get the band structure of graphene under the effect of an electric field. The problem is that the result at the end is very messy and jiggly. I repeated the calculations many times but I still get the same result. I first performed a scf calculation without the electric field followed by a scf calculation with an electric field and then the band calculation. Do you have some evidence that your "messy and jiggly" band structure is wrong? Are you sure that you are visualizing it in the correct way? HTH GS SCF with electric field &control prefix='bi elgraphene', calculation='scf', restart_mode='from_scratch', lelfield = .true., pseudo_dir = '/espresso-4.2/pseudo/', outdir='/tmp/results_MOUJAES/' / &system ibrav= 4, celldm(1) =4.608737, celldm(3)=5.330410, nat=4, ntyp= 1, ecutwfc = 110.D0,occupations='smearing',smearing='methfessel-paxton', degauss=0.01 / &electrons conv_thr=1.D-10, mixing_mode='plain' efield_cart(1) = 0.0, efield_cart(2) = 0.0, efield_cart(3) = 0.001, startingwfc = 'random' / ATOMIC_SPECIES C 12.0107 C.pz-vbc.UPF ATOMIC_POSITIONS crystal C 0.000000 0.000000 0.000000 C 0.000000 0.000000 0.257692 C 0.333333 -0.33333 0.000000 C -0.333333 0.33333 0.257692 K_POINTS automatic 38 38 1 0 0 0 I noticed that part of the bands calculation output had a problem with the convergence of one of thh eigenavalues as some of the input looked like: per-process dynamical memory: 30.2 Mb Band Structure Calculation Davidson diagonalization with overlap c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged c_bands: 1 eigenvalues not converged Please can anyone suggest me of what could have gone wrong... Thanks Elie Moujaes University of Nottingham NG7 2RD UK _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -- Gabriele Sclauzero, EPFL SB ITP CSEA PH H2 462, Station 3, CH-1015 Lausanne _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100930/c21ec792/attachment-0001.htm -------------- next part -------------- A non-text attachment was scrubbed... Name: bigraphel.tif Type: image/tiff Size: 102582 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20100930/c21ec792/attachment-0001.tif
