Thanks for your help. I read in mail-archive.com that this spinel work fine with 2 formula units but I cannot found how reducre from 8 formula units to 2 formula units.
On Tue, Jul 7, 2015 at 5:33 AM, Giovanni Cantele < [email protected]> wrote: > if you want to optimize the structure (that is, the lattice constant), I > would say that you cannot use few atoms. > > Convergence of the total energy with respect to the cutoff is a property > of the pseudo potentials, so you could check the variations > of the total energy with respect to ecutwfc by considering one atom for > each atomic species in a cubic supercell. However, the convergence > of other properties, that are proper of the crystal, e.g. bulk modulus, > phonon frequencies, and so on require using the full system. > > For the case of alat (lattice parameter) in principle you should relax the > system at each value of alat. > > Giovanni > > > > > On 07 Jul 2015, at 10:33, max <[email protected]> wrote: > > Thanks for the fast response. *definitely need 56 atoms*. Thats mean that > cannot use few atoms for convergence test and optimize the structure. > > If you can, can you suggest me some tricks for convergence test with this > lot of atoms? > > I need run relax calculation before run scf for ecut and alat convergence > test? > > On Tue, Jul 7, 2015 at 4:01 AM, Giovanni Cantele < > [email protected]> wrote: > >> As far as I understand, the LiMn2O4 has 8 formula units in one unit cell, >> so you definitely need 56 atoms in the unit cell. >> >> The cif file contains only information on the inequivalent atoms, all >> others can be obtained from the former by applying the >> coordinate transformation of the space group Fd-3m >> >> A useful way to do that, as specified here: >> >> http://www.quantum-espresso.org/faq/input-data/#3.2 >> >> is to run the converter from cif files included in the QE distribution. >> >> espresso-5.2.0/PW/tools/cif2qe.sh 1513984 > 1513984.scf.in >> >> This produces a file (that you might want to check for correctness and to >> modify according to your needs) that looks like >> >> >> &CONTROL >> title = '1513984' >> calculation = 'relax' >> restart_mode = 'from_scratch' >> outdir = './1' >> pseudo_dir = '../PP/atompaw' >> prefix = '1513984' >> disk_io = 'none' >> verbosity = 'default' >> etot_conv_thr = 0.0001 >> forc_conv_thr = 0.001 >> nstep = 400 >> tstress = .true. >> tprnfor = .true. >> / >> &SYSTEM >> ibrav = 0 >> nat = 56 >> ntyp = 3 >> ecutwfc = 60 >> ecutrho = 480 >> vdw_corr = 'xdm' >> xdm_a1 = 1.2153 >> xdm_a2 = 2.3704 >> / >> &ELECTRONS >> electron_maxstep = 200 >> conv_thr = 1.0D-7 >> diago_thr_init = 1e-4 >> startingpot = 'atomic' >> startingwfc = 'atomic' >> mixing_mode = 'plain' >> mixing_beta = 0.5 >> mixing_ndim = 8 >> diagonalization = 'david' >> / >> &IONS >> ion_dynamics = 'bfgs' >> / >> >> ATOMIC_SPECIES >> Li1+ 0.0000000000 Li1+.pw86pbe-n-kjpaw_psl.1.0.0.UPF >> Mn3.5+ 0.0000000000 Mn3.5+.pw86pbe-n-kjpaw_psl.1.0.0.UPF >> O2- 0.0000000000 O2-.pw86pbe-n-kjpaw_psl.1.0.0.UPF >> >> ATOMIC_POSITIONS crystal >> Li1+ 0.87500000000000 0.87500000000000 0.87500000000000 >> Li1+ 0.12500000000000 0.12500000000000 0.12500000000000 >> Li1+ 0.87500000000000 0.37500000000000 0.37500000000000 >> Li1+ 0.37500000000000 0.87500000000000 0.37500000000000 >> Li1+ 0.37500000000000 0.37500000000000 0.87500000000000 >> Li1+ 0.12500000000000 0.62500000000000 0.62500000000000 >> Li1+ 0.62500000000000 0.12500000000000 0.62500000000000 >> Li1+ 0.62500000000000 0.62500000000000 0.12500000000000 >> Mn3.5+ 0.50000000000000 0.25000000000000 0.25000000000000 >> Mn3.5+ 0.25000000000000 0.50000000000000 0.25000000000000 >> Mn3.5+ 0.25000000000000 0.25000000000000 0.50000000000000 >> Mn3.5+ 0.50000000000000 0.50000000000000 0.50000000000000 >> Mn3.5+ 0.50000000000000 0.75000000000000 0.75000000000000 >> Mn3.5+ 0.75000000000000 0.50000000000000 0.75000000000000 >> Mn3.5+ 0.75000000000000 0.75000000000000 0.50000000000000 >> Mn3.5+ 0.00000000000000 0.25000000000000 0.75000000000000 >> Mn3.5+ 0.00000000000000 0.75000000000000 0.25000000000000 >> Mn3.5+ 0.25000000000000 0.00000000000000 0.75000000000000 >> Mn3.5+ 0.75000000000000 0.00000000000000 0.25000000000000 >> Mn3.5+ 0.25000000000000 0.75000000000000 0.00000000000000 >> Mn3.5+ 0.75000000000000 0.25000000000000 0.00000000000000 >> Mn3.5+ 0.50000000000000 0.00000000000000 0.00000000000000 >> Mn3.5+ 0.00000000000000 0.50000000000000 0.00000000000000 >> Mn3.5+ 0.00000000000000 0.00000000000000 0.50000000000000 >> O2- 0.73730000000000 0.01270000000000 0.01270000000000 >> O2- 0.01270000000000 0.73730000000000 0.01270000000000 >> O2- 0.01270000000000 0.01270000000000 0.73730000000000 >> O2- 0.73730000000000 0.73730000000000 0.73730000000000 >> O2- 0.26270000000000 0.98730000000000 0.98730000000000 >> O2- 0.98730000000000 0.26270000000000 0.98730000000000 >> O2- 0.98730000000000 0.98730000000000 0.26270000000000 >> O2- 0.26270000000000 0.26270000000000 0.26270000000000 >> O2- 0.73730000000000 0.51270000000000 0.51270000000000 >> O2- 0.23730000000000 0.01270000000000 0.51270000000000 >> O2- 0.23730000000000 0.51270000000000 0.01270000000000 >> O2- 0.01270000000000 0.23730000000000 0.51270000000000 >> O2- 0.51270000000000 0.73730000000000 0.51270000000000 >> O2- 0.51270000000000 0.23730000000000 0.01270000000000 >> O2- 0.01270000000000 0.51270000000000 0.23730000000000 >> O2- 0.51270000000000 0.01270000000000 0.23730000000000 >> O2- 0.51270000000000 0.51270000000000 0.73730000000000 >> O2- 0.73730000000000 0.23730000000000 0.23730000000000 >> O2- 0.23730000000000 0.73730000000000 0.23730000000000 >> O2- 0.23730000000000 0.23730000000000 0.73730000000000 >> O2- 0.26270000000000 0.48730000000000 0.48730000000000 >> O2- 0.76270000000000 0.98730000000000 0.48730000000000 >> O2- 0.76270000000000 0.48730000000000 0.98730000000000 >> O2- 0.98730000000000 0.76270000000000 0.48730000000000 >> O2- 0.48730000000000 0.26270000000000 0.48730000000000 >> O2- 0.48730000000000 0.76270000000000 0.98730000000000 >> O2- 0.98730000000000 0.48730000000000 0.76270000000000 >> O2- 0.48730000000000 0.98730000000000 0.76270000000000 >> O2- 0.48730000000000 0.48730000000000 0.26270000000000 >> O2- 0.26270000000000 0.76270000000000 0.76270000000000 >> O2- 0.76270000000000 0.26270000000000 0.76270000000000 >> O2- 0.76270000000000 0.76270000000000 0.26270000000000 >> >> K_POINTS automatic >> 2 2 2 0 0 0 >> >> CELL_PARAMETERS >> 15.57115429380366 0.00000000000000 0.00000000000000 >> 0.00000000000000 15.57115429380366 0.00000000000000 >> 0.00000000000000 0.00000000000000 15.57115429380366 >> >> >> >> Giovanni >> >> >> >> On 06 Jul 2015, at 20:51, max <[email protected]> wrote: >> >> Hello, >> >> I'm confusing, I need to do some convergence test, but I don't know if I >> need primitive or one unit cell and how to select it. >> >> I'm using this structure http://www.crystallography.net/cod/1513984.html >> >> I extracted the crystallographic translation. The cell formula units are >> 8, has 56 atoms. See ATOMIC_POSITIONS bellow. >> >> One unit cell of LiMn2O4 (spinel) has 7 atoms. >> >> I have the following questions: >> >> >> >> *Do I need to put 7 atoms in the primitive cell or how many?How can I >> select the atoms position for primitive or one unit cell?* >> >> ATOMIC_POSITIONS alat >> Li 0.125000000 0.125000000 0.125000000 >> Li -0.125000000 0.875000000 0.875000000 >> Li 0.875000000 -0.125000000 0.875000000 >> Li 0.875000000 0.875000000 -0.125000000 >> Li -0.125000000 -0.125000000 -0.125000000 >> Li -0.125000000 0.375000000 0.375000000 >> Li 0.375000000 0.875000000 0.375000000 >> Li 0.875000000 0.375000000 0.375000000 >> Mn 0.500000000 0.500000000 0.500000000 >> Mn -0.500000000 1.250000000 1.250000000 >> Mn 1.250000000 -0.500000000 1.250000000 >> Mn 1.250000000 1.250000000 -0.500000000 >> Mn -0.500000000 -0.500000000 -0.500000000 >> Mn 0.500000000 -0.250000000 -0.250000000 >> Mn -0.250000000 0.500000000 -0.250000000 >> Mn -0.250000000 -0.250000000 0.500000000 >> Mn -0.500000000 0.750000000 0.750000000 >> Mn 0.000000000 1.250000000 0.750000000 >> Mn 0.000000000 0.750000000 1.250000000 >> Mn 1.250000000 0.000000000 0.750000000 >> Mn 0.750000000 -0.500000000 0.750000000 >> Mn 0.750000000 0.000000000 1.250000000 >> Mn 1.250000000 0.750000000 0.000000000 >> Mn 0.750000000 1.250000000 0.000000000 >> O -0.262700000 1.012700000 1.012700000 >> O 1.012700000 -0.262700000 1.012700000 >> O 1.012700000 1.012700000 -0.262700000 >> O -0.262700000 -0.262700000 -0.262700000 >> O 0.262700000 -0.012700000 -0.012700000 >> O -0.012700000 0.262700000 -0.012700000 >> O -0.012700000 -0.012700000 0.262700000 >> O 0.262700000 0.262700000 0.262700000 >> O -0.262700000 0.512700000 0.512700000 >> O 0.237300000 1.012700000 0.512700000 >> O 0.237300000 0.512700000 1.012700000 >> O 1.012700000 0.237300000 0.512700000 >> O 0.512700000 -0.262700000 0.512700000 >> O 0.512700000 0.237300000 1.012700000 >> O 1.012700000 0.512700000 0.237300000 >> O 0.512700000 1.012700000 0.237300000 >> O 0.512700000 0.512700000 -0.262700000 >> O -0.262700000 0.237300000 0.237300000 >> O 0.237300000 -0.262700000 0.237300000 >> O 0.237300000 0.237300000 -0.262700000 >> O 0.262700000 0.487300000 0.487300000 >> O 0.762700000 -0.012700000 0.487300000 >> O 0.762700000 0.487300000 -0.012700000 >> O -0.012700000 0.762700000 0.487300000 >> O 0.487300000 0.262700000 0.487300000 >> O 0.487300000 0.762700000 -0.012700000 >> O -0.012700000 0.487300000 0.762700000 >> O 0.487300000 -0.012700000 0.762700000 >> O 0.487300000 0.487300000 0.262700000 >> O 0.262700000 0.762700000 0.762700000 >> O 0.762700000 0.262700000 0.762700000 >> O 0.762700000 0.762700000 0.262700000 >> >> -- >> Máximo Ramírez >> Physics Degree >> Universidad Autónoma de Santo Domingo >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> >> >> -- >> >> Giovanni Cantele, PhD >> CNR-SPIN >> c/o Dipartimento di Fisica >> Universita' di Napoli "Federico II" >> Complesso Universitario M. S. Angelo - Ed. 6 >> Via Cintia, I-80126, Napoli, Italy >> e-mail: [email protected] >> Phone: +39 081 676910 >> Skype contact: giocan74 >> >> ResearcherID: http://www.researcherid.com/rid/A-1951-2009 >> Web page: http://people.na.infn.it/~cantele >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > > -- > El éxito solo es para los que se arriesgan por sus objetivos. > > Máximo Ramírez Mateo > Desarrollador de Software > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > > > -- > > Giovanni Cantele, PhD > CNR-SPIN > c/o Dipartimento di Fisica > Universita' di Napoli "Federico II" > Complesso Universitario M. S. Angelo - Ed. 6 > Via Cintia, I-80126, Napoli, Italy > e-mail: [email protected] > Phone: +39 081 676910 > Skype contact: giocan74 > > ResearcherID: http://www.researcherid.com/rid/A-1951-2009 > Web page: http://people.na.infn.it/~cantele > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- El éxito solo es para los que se arriesgan por sus objetivos. Máximo Ramírez Mateo Desarrollador de Software
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