date:20151005

Re: [Pw_forum] NiZn ferrite - magnetic moment

2015-10-05 Thread chaitanya varma

Respected AriesThank you, i will check for convergence and see whether i can 
use PAW without LDA+U for this system.regards Chaitanya Varma M   


 On Monday, 5 October 2015 7:52 PM, Arles V. Gil Rebaza  
wrote:
   

 Dear Chaitanya, are you sure that this values, describe fine your system
 ecutwfc = 80 ,
ecutrho = 320 
Have your test the convergence of this parameters.

And your calculation crahs because:  forces for this U_projection_type not 
implemented. with PAW pseudopotentials

Best

Arles V. Gil Rebaza
IFLP-Argentina.

2015-10-05 2:14 GMT-03:00 chaitanya varma :

Respected all,I tried to work out magnetization of ni-Zn ferrite 
(Ni0.5Zn0.5Fe2O4) using vc-relax run.From experimental data and my work on 
Ni-Zn ferrite (bulk & nanopowders) the magnetic moment is 2.5 bohr magnetons 
for formula unit or 20 bohr magnetons per unit cell (8 molecular formulas).but 
I am getting 0.03 bohr magnetons.
Please give me suggestions to improve the calculation.
 
 calculation = 'vc-relax' ,
    restart_mode = 'from_scratch' ,
  wf_collect = .true. ,
  outdir = '/home/mcv/build/qe/' ,
  wfcdir = '/home/mcv/build/qe/' ,
  pseudo_dir = '/home/mcv/build/qe/espresso-5.2.0/pseudo/' ,
  prefix = 'Ni-Zn' ,
 lkpoint_dir = .true. ,
 disk_io = 'high' ,
   verbosity = 'high' ,
 /
 
   ibrav = 2,
   celldm(1) = 15.87842,
 nat = 56,
    ntyp = 5,
 ecutwfc = 80 ,
 ecutrho = 320 ,
    nbnd = 440,
 occupations = 'smearing' ,
 degauss = 0.02 ,
    smearing = 'marzari-vanderbilt' ,
   nspin = 2 ,
   starting_magnetization(1) = 1,
   starting_magnetization(2) = 1,
   starting_magnetization(4) = 1,
  lda_plus_u = .true. ,
 lda_plus_u_kind = 1 ,
    Hubbard_U(1) = 4.5,
    Hubbard_U(2) = 4.5,
    Hubbard_U(4) = 4.0,
   Hubbard_J0(1) = 1.0,
   Hubbard_J0(2) = 1.0,
   Hubbard_J0(4) = 1.0,
   U_projection_type = 'ortho-atomic' ,
 /
 
   scf_must_converge = .true. ,
 mixing_mode = 'local-TF' ,
 mixing_beta = 0.5 ,
 diagonalization = 'david' ,
 /
 
    ion_dynamics = 'bfgs' ,
 /
 
   cell_dynamics = 'bfgs' ,
 cell_dofree = 'xyz' ,
 /
ATOMIC_SPECIES
  FeT   55.84500  Fe.pbesol-spn-kjpaw_psl.0.2.1.UPF 
  FeO   55.84500  Fe.pbesol-spn-kjpaw_psl.0.2.1.UPF 
  ZnT   65.38200  Zn.pbesol-spn-kjpaw_psl.0.3.1.UPF 
  NiO   58.69340  Ni.pbesol-spn-kjpaw_psl.0.3.1.UPF 
    O   15.99940  O.pbesol-n-kjpaw_psl.0.1.UPF 
ATOMIC_POSITIONS crystal 
  ZnT  0.0    0.0    0.0    
  FeO  0.62500    0.62500    0.62500    
    O  0.38250    0.38250    0.38250    
  ZnT  0.0    0.5    0.5    
  FeT  0.5    0.5    0.0    
  ZnT  0.5    0.0    0.5    
  FeT  0.75000    0.25000    0.75000    
  ZnT  0.25000    0.25000    0.25000    
  FeT  0.25000    0.75000    0.75000    
  FeT  0.75000    0.75000    0.25000    
  NiO  0.37500    0.87500    0.12500    
  FeO  0.87500    0.12500    0.37500    
  NiO  0.12500    0.37500    0.87500    
  FeO  0.87500    0.37500    0.12500    
  NiO  0.37500    0.12500    0.87500    
  FeO  0.12500    0.87500    0.37500    
  FeO  0.62500    0.12500    0.12500    
  FeO  0.37500    0.37500    0.62500    
  FeO  0.87500    0.62500    0.87500    
  NiO  0.87500    0.87500    0.62500    
  FeO  0.37500    0.62500    0.37500    
  FeO  0.12500    0.62500    0.12500    
  FeO  0.62500    0.37500    0.37500    
  FeO  0.62500    0.87500    0.87500    
  FeO  0.12500    0.12500    0.62500    
    O  0.61700    0.11749    0.88250    
    O  0.11700    0.88250    0.61700    
    O  0.88250    0.61700    0.11740    
    O  0.13249    0.63244    0.36750    
    O  0.86750    0.86750    0.86750    
    O  0.63244    0.36750    0.13249    
    O  0.36750    0.13249    0.63244    
    O  0.63244    0.13249    0.36750    
    O  0.13249    0.36750    0.63244    
    O  0.36750    0.63244    0.13249    
    O  0.11749    0.61700

[Pw_forum] Total potential under Berry phase electric field

2015-10-05 Thread Mostafa Youssef

Dear all,

I plotted the total potential (bare + Hartee + xc) for MgO under finite 
electric field applied via Berry Phase approach. This is basically example 09 
in  CPV/examples and I run the same calculation also using PWscf.  Attached is 
the result. In particular the macroscopic average of the total potential is 
zero.  Is the total scalar potential really flat under electric field applied 
via Berry phase or is there something wrong with what the code prints as the 
total potential?

I'm still trying to understand how the electric field is applied in this case , 
in particular how the non-periodicity of the scalar potential is avoided.

Any thoughts or references are highly appreciated.

Mostafa Youssef
MIT


MgO_poential.pdf
Description: MgO_poential.pdf
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[Pw_forum] Irregular phonon dispersion

2015-10-05 Thread Cameron Foss

I am trying to calculate phonons in monolayer (ML) mos2 along high symmetry
paths, I am using the same input file that gave me a good electronic band
structure. I am using espresso-5.1. The scf and ph input files are pasted
below. I have also attached a .tif file of the dispersion, please notice
that near the Gamma points there is some significant irregularity.

I am curious to know why this input file worked OK for the electronic band
structure but not so well for phonons? For clarity I used an 8x8x1 MP grid
for the electronic band structure calculation and a 6x6x4 MP grid for
phonons. (I had good success using a 6x6x4 MP grid for calculating phonons
in ML mos2 before however I used the wrong lattice constants putting the
structure under strain thus the purpose of this new calculation).

I understand the vdW forces may play a role in electronic band calculations
of MLs so the interplanar distance is ~15 angstroms for both the electronic
band calculation and phonons calculation.

SCF CALC

calculation='scf',
restart_mode='from_scratch',
pseudo_dir='/home/cf79a/espresso-par/espresso-5.1.2/pseudo',

outdir='/home/cf79a/espresso-par/espresso-5.1.2/materials/EFRI/outdir/MoS2',
prefix='MoS2-lda',
/

ibrav=4, celldm(1)=5.905393714, celldm(3)=6,
nat=3, ntyp=2, ecutwfc =140
/

conv_thr =  1.0d-15
mixing_beta = 0.7
/
ATOMIC_SPECIES
 Mo  95.94Mo.pw-mt_fhi.UPF
 S   32.065   S.pw-mt_fhi.UPF
ATOMIC_POSITIONS bohr
S0.2  -0.1   0.0
Mo   2.952696857   1.704740325   2.938523912
S0.2  -0.1   5.877047824
K_POINTS automatic
  6 6 4 1 1 1

%PHONONS
phonons of MoS2

  recover=.true.,
  tr2_ph=1.0d-12,
  ldisp=.true.,
  nq1=6, nq2=6, nq3=4
  amass(1)=95.94,
  amass(2)=32.065,
  prefix='MoS2-lda',
  !outdir='directory where large files are written/'

outdir='/home/cf79a/espresso-par/espresso-5.1.2/materials/EFRI/outdir/MoS2',
  fildyn='mos.dyn',
 /

Best,
Cameron
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Re: [Pw_forum] NiZn ferrite - magnetic moment

2015-10-05 Thread Arles V. Gil Rebaza

Dear Chaitanya, are you sure that this values, describe fine your system
ecutwfc = 80 ,
ecutrho = 320
Have your test the convergence of this parameters.

And your calculation crahs because:  forces for this U_projection_type not
implemented. with PAW pseudopotentials

Best

Arles V. Gil Rebaza
IFLP-Argentina.

2015-10-05 2:14 GMT-03:00 chaitanya varma :

> Respected all,
> I tried to work out magnetization of ni-Zn ferrite (Ni0.5Zn0.5Fe2O4) using
> vc-relax run.
> From experimental data and my work on Ni-Zn ferrite (bulk & nanopowders)
> the magnetic moment is 2.5 bohr magnetons for formula unit or 20 bohr
> magnetons per unit cell (8 molecular formulas).
> but I am getting 0.03 bohr magnetons.
>
> Please give me suggestions to improve the calculation.
>
>  
>  calculation = 'vc-relax' ,
> restart_mode = 'from_scratch' ,
>   wf_collect = .true. ,
>   outdir = '/home/mcv/build/qe/' ,
>   wfcdir = '/home/mcv/build/qe/' ,
>   pseudo_dir = '/home/mcv/build/qe/espresso-5.2.0/pseudo/'
> ,
>   prefix = 'Ni-Zn' ,
>  lkpoint_dir = .true. ,
>  disk_io = 'high' ,
>verbosity = 'high' ,
>  /
>  
>ibrav = 2,
>celldm(1) = 15.87842,
>  nat = 56,
> ntyp = 5,
>  ecutwfc = 80 ,
>  ecutrho = 320 ,
> nbnd = 440,
>  occupations = 'smearing' ,
>  degauss = 0.02 ,
> smearing = 'marzari-vanderbilt' ,
>nspin = 2 ,
>starting_magnetization(1) = 1,
>starting_magnetization(2) = 1,
>starting_magnetization(4) = 1,
>   lda_plus_u = .true. ,
>  lda_plus_u_kind = 1 ,
> Hubbard_U(1) = 4.5,
> Hubbard_U(2) = 4.5,
> Hubbard_U(4) = 4.0,
>Hubbard_J0(1) = 1.0,
>Hubbard_J0(2) = 1.0,
>Hubbard_J0(4) = 1.0,
>U_projection_type = 'ortho-atomic' ,
>  /
>  
>scf_must_converge = .true. ,
>  mixing_mode = 'local-TF' ,
>  mixing_beta = 0.5 ,
>  diagonalization = 'david' ,
>  /
>  
> ion_dynamics = 'bfgs' ,
>  /
>  
>cell_dynamics = 'bfgs' ,
>  cell_dofree = 'xyz' ,
>  /
> ATOMIC_SPECIES
>   FeT   55.84500  Fe.pbesol-spn-kjpaw_psl.0.2.1.UPF
>   FeO   55.84500  Fe.pbesol-spn-kjpaw_psl.0.2.1.UPF
>   ZnT   65.38200  Zn.pbesol-spn-kjpaw_psl.0.3.1.UPF
>   NiO   58.69340  Ni.pbesol-spn-kjpaw_psl.0.3.1.UPF
> O   15.99940  O.pbesol-n-kjpaw_psl.0.1.UPF
> ATOMIC_POSITIONS crystal
>   ZnT  0.00.00.0
>   FeO  0.625000.625000.62500
> O  0.382500.382500.38250
>   ZnT  0.00.50.5
>   FeT  0.50.50.0
>   ZnT  0.50.00.5
>   FeT  0.750000.250000.75000
>   ZnT  0.250000.250000.25000
>   FeT  0.250000.750000.75000
>   FeT  0.750000.750000.25000
>   NiO  0.375000.875000.12500
>   FeO  0.875000.125000.37500
>   NiO  0.125000.375000.87500
>   FeO  0.875000.375000.12500
>   NiO  0.375000.125000.87500
>   FeO  0.125000.875000.37500
>   FeO  0.625000.125000.12500
>   FeO  0.375000.375000.62500
>   FeO  0.875000.625000.87500
>   NiO  0.875000.875000.62500
>   FeO  0.375000.625000.37500
>   FeO  0.125000.625000.12500
>   FeO  0.625000.375000.37500
>   FeO  0.625000.875000.87500
>   FeO  0.125000.125000.62500
> O  0.617000.117490.88250
> O  0.117000.882500.61700
> O  0.882500.617000.11740
> O  0.132490.632440.36750
> O  0.867500.867500.86750
> O  0.632440.367500.13249
> O  0.367500.132490.63244
> O  0.632440.132490.36750
> O  0.132490.367500.63244
> O  0.367500.632440.13249
> O  0.117490.617000.88250
> O  0.617000.882500.11749
> O  0.882500.117490.61700
> O  0.382500.882500.88250
>

[Pw_forum] Good values for Dispersion interactions parameters

2015-10-05 Thread Venkataramana Imandi

Dear all

How to take good values of london_s6 and london_rcut for bulk Iridium
(total atoms:72). Similarly, how to determine landon_s6 and london_rcut
values for Iridium using any mathematical formula instead of taking default
values from the QE keywords list.
Any suggestions are valuable to me. I am anticipatively thanks.


venkataramana
PhD student,
IIT Bombay
Mumbai
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Re: [Pw_forum] Cohesive energy of bulk Iridium

2015-10-05 Thread Venkataramana Imandi

 Dear sir,

I have done calculations according your suggestions.
I got cohesive energy at 0 K is as follows.
934.7 kJ/mol
749.6 kJ/mol (with dispersion correction)
731.7 kJ/mol (with 2x2x1 k-point)
670.0 kJ/mol (Experiment at 0 K)

I increased plane wave cutoff to 35 to 40 Ryd., there is no change in the
values.

I got surface energy as follows.
11.7 kJ/mol/Angstrom^2
28.4 kJ/mol/Angstrom^2 (with dispersion correction)
28.4 kJ/mol/Angstrom^2 (with 2x2x1 k-point)
14.9 kJ/mol/Angstrom^2 (Experiment at 0 K)

How to refine my results in such way that i will get close to experimental
results by tuning input parameters. Please suggest and your information is
valuable to me.
In single Iridium case, the input file contains additional nspin=2 and
starting_magnetization(1)=1 parameters and I didn't include those
parameters in the bulk Iridium case.
I am attaching one input file with dispersion correction as shown below.


 Structure: Ir fcc(111) ; (3x2x2) SUPER-CELL

 
 6 Layers slab



calculation='relax',
prefix='ir_ch',
nstep=5000,
   etot_conv_thr=1.0D-5,
   forc_conv_thr=1.0D-4,
   pseudo_dir = '/home/venkat/ORR1/PPS1'
 /

   ibrav=0,
nat=72,
ntyp=1,
  ecutwfc = 35.D0,
  ecutrho=350.D0,
 nosym=.true.,
occupations='smearing',
smearing='m-p',
 degauss=0.07D0,
 vdw_corr='grimme-d2'
/

   electron_maxstep=2000,
  diagonalization='david',
   mixing_beta = 0.7D0,
conv_thr =  1.0D-8,
   scf_must_converge=.true.
  mixing_mode = 'local-TF' ,
  startingpot = 'atomic' ,
   startingwfc = 'atomic' ,
/

ion_dynamics='bfgs'
/
ATOMIC_SPECIES
Ir   192.217   Ir.pw91-n-rrkjus_psl.0.2.3.UPF

CELL_PARAMETERS angstrom
  8.14374880.0.
  0.0009.403591120.
  0.0000.   13.29868610

ATOMIC_POSITIONS angstrom
Ir   6.78645733  5.48542817  6.64934305
Ir   5.42916587  7.83632593  6.64934305
Ir   5.42916587  4.70179556  4.43289536
Ir   6.78645733  7.05269336  4.43289536
Ir   5.42916587  6.26906075  2.21644768
Ir   6.78645733  8.61995854  2.21644768
Ir   4.07187440  5.48542817  6.64934305
Ir   2.71458293  7.83632593  6.64934305
Ir   2.71458293  4.70179556  4.43289536
Ir   4.07187440  7.05269336  4.43289536
Ir   2.71458293  6.26906075  2.21644768
Ir   4.07187440  8.61995854  2.21644768
Ir   1.35729146  5.48542817  6.64934305
Ir   0.  7.83632593  6.64934305
Ir   0.  4.70179556  4.43289536
Ir   1.35729146  7.05269336  4.43289536
Ir   0.  6.26906075  2.21644768
Ir   1.35729146  8.61995854  2.21644768
Ir   6.78645733  0.78363261  6.64934305
Ir   5.42916587  3.13453037  6.64934305
Ir   5.42916587  0.  4.43289536
Ir   6.78645733  2.35089780  4.43289536
Ir   5.42916587  1.56726519  2.21644768
Ir   6.78645733  3.91816298  2.21644768
Ir   4.07187440  0.78363261  6.64934305
Ir   2.71458293  3.13453037  6.64934305
Ir   2.71458293  0.  4.43289536
Ir   4.07187440  2.35089780  4.43289536
Ir   2.71458293  1.56726519  2.21644768
Ir   4.07187440  3.91816298  2.21644768
Ir   1.35729146  0.78363261  6.64934305
Ir   0.  3.13453037  6.64934305
Ir   0.  0.  4.43289536
Ir   1.35729146  2.35089780  4.43289536
Ir   0.  1.56726519  2.21644768
Ir   1.35729146  3.91816298  2.21644768
Ir   6.78645733  5.48542817  0.
Ir   5.42916587  7.83632593  0.
Ir   5.42916587  4.70179556 -2.21644769
Ir   6.78645733  7.05269336 -2.21644769
Ir   5.42916587  6.26906075 -4.43289537
Ir   6.78645733  8.61995854 -4.43289537
Ir   4.07187440  5.48542817  0.
Ir   2.71458293  7.83632593  0.
Ir   2.71458293

Re: [Pw_forum] NiZn ferrite - magnetic moment

[Pw_forum] Total potential under Berry phase electric field

[Pw_forum] Irregular phonon dispersion

Re: [Pw_forum] NiZn ferrite - magnetic moment

[Pw_forum] Good values for Dispersion interactions parameters

Re: [Pw_forum] Cohesive energy of bulk Iridium

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