On Wed, Dec 14, 2016 at 3:00 PM, sayan chaudhuri <[email protected]> wrote:
> How to get rid of the small unit cell problem? what is the "small unit cell problem"? Paolo > When it is a pure system, Wycoff positions with Atomic positions card set > at alat works. So, is there any definite procedure to give the position of > the atoms in the system when I am doping in the system? > > Thanking you, > Sayan Chaudhuri > > On Fri, Dec 9, 2016 at 7:07 PM, Lorenzo Paulatto > <[email protected]> wrote: >> >> It may be difficult to converge LDA+U calculations in general, starting >> with >> initial magnetizations that aren't absurd may help >> >> hth >> >> On Friday, December 9, 2016 5:29:01 PM CET Максим Арсентьев wrote: >> > Dear Lorenzo, >> > >> > I have the same problem - cannot achieve SCF convergence. I use higher >> > ecutwfc = 39.0, ecutrho = 300 but not coverging. >> > >> > Regards, Maxim Arsentev. >> > >> > 2016-12-09 12:52 GMT+04:00 Lorenzo Paulatto >> > <[email protected]> >> > > Dear Sayan, >> > > it looks to me like your unit cell is too small, the atoms are all >> > > crumped >> > > together. Please note that celldm(1) is specified in bohr atomic >> > > units. >> > > >> > > Also: >> > > 1. a cutoff of 30Ry is probably very small for BHS pseudopotentials >> > > 2. ecutrho=default (4*ecutwfc ) is probably not enough for all the >> > > ultrasoft >> > > pseudopotentials you are using >> > > >> > > I would recommend you first spend some time reproducin the >> > > single-element >> > > metal, and once you can correctly reproduce geometry, band structure, >> > > physical >> > > properties, you move to simulating the alloy. >> > > >> > > HTH >> > > >> > > On Friday, December 9, 2016 1:59:44 PM CET sayan chaudhuri wrote: >> > > > Hi, >> > > > >> > > > I am running QE self - consistently for my heusler alloy(Fe2TiSn) >> > > > >> > > > system, where 25% of Sn were replaced by Sb. But after 800 >> > > > iterations >> > > > and >> > > > almost 3 hours of running also still it is not converged. >> > > > The code I am using is added bellow. Please tell me what is the >> > > > source >> > > > of >> > > > error. >> > > > >> > > > Thanking you, >> > > > >> > > > Sayan Chaudhuri >> > > > >> > > > *&control prefix='fts', calculation = 'scf', verbosity = >> > > > 'low', pseudo_dir = '/home/ltp/Desktop/espresso-5.4.0/pseudo', >> > > > outdir = './tmp', / &system ibrav=2 celldm(1)=11.43, >> > > > nat=16, ntyp=4, nspin=2, ecutwfc=30.0, >> > > > starting_magnetization(1) = 0.0, starting_magnetization(2) = >> > > > 0.0, >> > > > starting_magnetization(3) = 0.5, starting_magnetization(3) = >> > > > 0.0, >> > > > occupations='tetrahedra', / &electrons electron_maxstep = >> > > > 3000, >> > > > diagonalization = 'david', mixing_mode = 'plain', conv_thr = >> > > > 1e-8, >> > > > mixing_beta=0.1, /ATOMIC_SPECIES Sb 121.76 Sb.pz-bhs.UPF Sn >> > > > 118.71 Sn.pz-dn-rrkjus_psl.0.2.UPF Fe 55.845 >> > > > Fe.pz-sp-van_ak.UPF >> > > > Ti 47.867 Ti.pz-sp-van.UPFATOMIC_POSITIONS {crystal} Sb >> > > > 0.000000000 0.000000000 0.000000000 Sn >> > > > 0.000000000 0.500000000 0.500000000 Sn >> > > > 0.500000000 0.000000000 0.500000000 Sb >> > > > 0.500000000 0.500000000 0.000000000 Fe >> > > > 0.250000000 0.250000000 0.250000000 Fe >> > > > 0.750000000 0.750000000 0.750000000 Fe >> > > > 0.750000000 0.750000000 0.250000000 Fe >> > > > 0.250000000 0.250000000 0.750000000 Fe >> > > > 0.750000000 0.250000000 0.750000000 Fe >> > > > 0.250000000 0.750000000 0.250000000 Fe >> > > > 0.250000000 0.750000000 0.750000000 Fe >> > > > 0.750000000 0.250000000 0.250000000 Ti >> > > > 0.500000000 0.500000000 0.500000000 Ti >> > > > 0.500000000 0.000000000 0.000000000 Ti >> > > > 0.000000000 0.500000000 0.000000000 Ti >> > > > 0.000000000 0.000000000 0.500000000 K_POINTS >> > > > {automatic} >> > > > 2 2 2 0 0 0* >> > > >> > > -- >> > > Dr. Lorenzo Paulatto >> > > IdR @ IMPMC -- CNRS & Université Paris 6 >> > > phone: +33 (0)1 44275 084 / skype: paulatz >> > > www: http://www-int.impmc.upmc.fr/~paulatto/ >> > > mail: 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris >> > > Cédex 05 >> > > >> > > _______________________________________________ >> > > Pw_forum mailing list >> > > [email protected] >> > > http://pwscf.org/mailman/listinfo/pw_forum >> >> >> -- >> Dr. Lorenzo Paulatto >> IdR @ IMPMC -- CNRS & Université Paris 6 >> phone: +33 (0)1 44275 084 / skype: paulatz >> www: http://www-int.impmc.upmc.fr/~paulatto/ >> mail: 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05 >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum > > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
