On Nov 25, 2013, at 11:49 AM, Jos? Gadelha da Silva Filho <gadelha at fisica.ufc.br> wrote:
> I tried to calculate DOS for graphene nanoribbon with antiferromagnetic > (AFM) configuration. I used QE 4.1.2, QE 5.0 and QE 5.0.2. Unfortunately I > always take a FM ordering. I would like to know what is wrong in my input > data: > > > &control > calculation = 'scf' , > outdir = 'fita' , > pseudo_dir = 'pseudo' , > prefix = 'fita' , > verbosity = 'high' , > wf_collect=.true., > / > &system > ibrav=0, > nat = 10, > ntyp = 4, > ecutwfc = 93 , > nbnd = 60, > occupations = 'smearing' , > degauss = 0.008 , > nspin = 2, > starting_magnetization(1) = 1.0, > starting_magnetization(2) = -1.0, > starting_magnetization(3) = 1.0, > starting_magnetization(4) = -1.0, > / > &electrons > diagonalization='david', > mixing_mode = 'plain', > mixing_beta = 0.7, > conv_thr = 1.0d-6, > / > ATOMIC_SPECIES > H1 1.007940 H.pw-mt_fhi.UPF > C1 12.010700 C.pw-mt_fhi.UPF > C2 12.010700 C.pw-mt_fhi.UPF > H2 1.007940 H.pw-mt_fhi.UPF > ATOMIC_POSITIONS crystal > H1 0.987129 0.348775 0.499998 > C1 0.987081 0.389095 0.500002 > C2 0.487078 0.413829 0.500002 > C1 0.486874 0.466305 0.500002 > C2 0.986871 0.491858 0.499998 > C1 0.986838 0.543986 0.500002 > C2 0.486787 0.569538 0.500002 > C1 0.486868 0.622014 0.500002 > C2 0.986868 0.646743 0.500002 > H2 0.986685 0.687058 0.499998 > CELL_PARAMETERS bohr > 4.705211 0.000000 0.000000 > 0.000000 52.410382 0.000000 > 0.000000 0.000000 16.588710 > > > K_POINTS automatic > 15 1 1 0 0 0 > > > Unless some serious bug is introduced in a version, changing QE version is not the degree of freedom I would investigate firstly!!! ;-) If you did not it previously, first check your input file using xcrysden (unfortunately I cannot do it at the moment because I've been unable to get a working xcrysden version under Mac Os X 10.8.5, but this is another story!). However, provided that your input structure is correct, I would not force initial magnetisation an ALL carbon atoms, also including hydrogens. It is not necessary to impose the initial magnetization on all atoms, just a small perturbation with respect to the zero-magnetization state is enough, at least in this case. Therefore, you can try just to set magnetization +0.5 and -0.5 on the two outermost (edge) C atoms, leaving all the other atoms (including H's) with no initial guess. Giovanni PS maybe you can reduce (to get a faster calculation) the 52 a.u. length of the second lattice vector and use an US pseudopotential for both H and C, allowing to drastically reduce the ecutwfc value. -- Giovanni Cantele, PhD CNR-SPIN c/o Dipartimento di Scienze Fisiche Universita' di Napoli "Federico II" Complesso Universitario M. S. Angelo - Ed. 6 Via Cintia, I-80126, Napoli, Italy e-mail: giovanni.cantele at spin.cnr.it Phone: +39 081 676910 Skype contact: giocan74 ResearcherID: http://www.researcherid.com/rid/A-1951-2009 Web page: http://people.na.infn.it/~cantele http://www.nanomat.unina.it -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20131125/6f8bb01e/attachment.html
