[Pw_forum] a question about MnSe

mohnish pandey mohnish.iitk at gmail.com
Wed Jan 19 18:33:45 CET 2011


Dear Duy,
                    I have checked the k-mesh convergence as well as
convergence with respect to ecut.

On Wed, Jan 19, 2011 at 10:49 PM, Duy Le <ttduyle at gmail.com> wrote:

> Did you check the k-mesh? Are 6 6 6 and 6 6 4 good for converged energy?
> --------------------------------------------------
> Duy Le
> PhD Student
> Department of Physics
> University of Central Florida.
>
> "Men don't need hand to do things"
>
>
>
> On Wed, Jan 19, 2011 at 11:57 AM, mohnish pandey <mohnish.iitk at gmail.com>
> wrote:
> > Dear QE users,
> >                            I am trying to do bulk calculations for MnSe
> in
> > rocksalt and wurtzite structure. Its has AFM ground state in rocksalt
> > structure but after checking convergence I am finding "rocksalt"
> structure
> > to be energetically higher than wurtzite structure. I am pasting my
> segments
> > of input and output files. Can anybody please help me in figuring out the
> > problem.
> > INPUT FOR ROCKSALT
> > &control
> >     calculation = 'vc-relax'
> >     restart_mode='restart',
> >     wf_collect = .true.
> >     prefix='mnse',
> >     pseudo_dir = '/home/mohnish/mnse-rocksalt-bulk',
> >     outdir='/home/mohnish/mnse-rocksalt-bulk',
> >     tprnfor = .true.,
> >     tstress=.true.
> >  /
> >  &system
> >     ibrav=  0, celldm(1)= 10.3026, nat=  4, ntyp= 3,
> >     ecutwfc = 40.0, ecutrho = 320.0,
> >     occupations='smearing', smearing='gauss', degauss=0.01,
> >     nspin=2,
> >     starting_magnetization(1)= 0.0,
> >     starting_magnetization(2)= 0.5,
> >     starting_magnetization(3)=-0.5,
> >  /
> >  &electrons
> >    diagonalization='david'
> >    mixing_mode = 'plain'
> >    mixing_beta = 0.4
> >    conv_thr = 1.0d-8
> >    startingpot = 'file'
> >    startingwfc = 'file'
> >  /
> > &IONS
> >   ion_dynamics='bfgs'
> >   trust_radius_max = 0.40
> >   trust_radius_ini = 0.20
> > /
> > &CELL
> >   cell_dynamics='bfgs',
> > /
> > ATOMIC_SPECIES
> >   Se  78.960 Se.pbe-van.UPF
> >   Mn1 54.938 Mn.pbe-sp-van_mit.UPF
> >   Mn2 54.938 Mn.pbe-sp-van_mit.UPF
> > CELL_PARAMETERS
> > 0.50 0.50 1.00
> > 0.50 1.00 0.50
> > 1.00 0.50 0.50
> > ATOMIC_POSITIONS {crystal}
> >  Se  0.25 0.25 0.25
> >  Se  0.75 0.75 0.75
> >  Mn1 0.0  0.0  0.0
> >  Mn2 0.5  0.5  0.5
> > K_POINTS {automatic}
> > 6 6 6 0 0 0
> > OUTPUT FOR ROCKSALT
> >  bfgs converged in   8 scf cycles and   4 bfgs steps
> >      (criteria: energy < 0.10E-03, force < 0.10E-02, cell < 0.50E+00)
> >      End of BFGS Geometry Optimization
> >      Final enthalpy =    -464.4688263706 Ry
> > Begin final coordinates
> >      new unit-cell volume =    533.55466 a.u.^3 (    79.06464 Ang^3 )
> > CELL_PARAMETERS (alat= 10.30260000)
> >    0.494008772   0.494008772   0.990589056
> >    0.494008772   0.990589056   0.494008772
> >    0.990589056   0.494008772   0.494008772
> > ATOMIC_POSITIONS (crystal)
> > Se       0.249999854   0.249999854   0.249999854
> > Se       0.750000146   0.750000146   0.750000146
> > Mn1      0.000000000   0.000000000   0.000000000
> > Mn2      0.500000000   0.500000000   0.500000000
> > End final coordinates
> > INPUT FOR WURTZITE
> > &control
> >     calculation = 'vc-relax',
> >     restart_mode='restart',
> >     verbosity = 'high'
> >     wf_collect = .true.
> >     outdir='/home/mohnish/mnse-wurtzite-bulk',
> >     pseudo_dir='/home/mohnish/mnse-wurtzite-bulk'
> >     prefix='mnse',
> >     tstress = .true.,
> >     tprnfor = .true.,
> > /
> >  &system
> >     ibrav=  4, a = 4.178, c = 6.783,nat= 4, ntyp= 3,
> >     ecutwfc =
> > 40,ecutrho=320,occupations='smearing',degauss=0.01,smearing='gaussian',
> >     nspin =2,starting_magnetization(1)=0.5,starting_magnetization(2)=
> -0.5,
> > /
> >  &electrons
> >    diagonalization='david'
> >    mixing_mode = 'plain'
> >    mixing_beta = 0.4
> >    conv_thr = 1.0d-8
> >    startingpot = 'file'
> >    startingwfc = 'file'
> >  /
> > &IONS
> >   ion_dynamics='bfgs'
> >   trust_radius_max = 0.40
> >   trust_radius_ini = 0.20
> > /
> > &CELL
> >   cell_dynamics='bfgs',
> > /
> > ATOMIC_SPECIES
> >   Mn1 54.938 Mn.pbe-sp-van_mit.UPF
> >   Mn2 54.938 Mn.pbe-sp-van_mit.UPF
> >   Se  78.960 Se.pbe-van.UPF
> > ATOMIC_POSITIONS (crystal)
> >   Mn1  0.000000000  0.000000000000  0.000000000
> >   Mn2  0.333333333  0.666666666667  0.500000000
> >   Se   0.000000000  0.000000000000  0.345000000
> >   Se   0.333333333  0.666666666667  0.845000000
> >  K_POINTS (automatic)
> >  6 6 4 0 0 0
> > OUTPUT FOR WURTZITE
> >  End of BFGS Geometry Optimization
> >      Final enthalpy =    -464.4799667612 Ry
> > Begin final coordinates
> >      new unit-cell volume =    681.36082 a.u.^3 (   100.96726 Ang^3 )
> > CELL_PARAMETERS (alat=  7.89527578)
> >    1.001414763   0.000000000   0.000000000
> >   -0.500707382   0.867250625   0.000000000
> >    0.000000000   0.000000000   1.594103933
> > ATOMIC_POSITIONS (crystal)
> > Mn1      0.000000000   0.000000000  -0.014999731
> > Mn2      0.333333333   0.666666667   0.485592670
> > Se       0.000000000   0.000000000   0.359333481
> > Se       0.333333333   0.666666667   0.860073579
> > End final coordinates
> >
> >
> >
> >
> > --
> > Regards,
> > MOHNISH,
> > -----------------------------------------------------------------
> > Mohnish Pandey
> > Y6927262,5th Year dual degree student,
> > Department of Chemical Engineering,
> > IIT KANPUR, UP, INDIA
> > -----------------------------------------------------------------
> >
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-- 
Regards,
MOHNISH,
-----------------------------------------------------------------
Mohnish Pandey
Y6927262,5th Year dual degree student,
Department of Chemical Engineering,
IIT KANPUR, UP, INDIA
-----------------------------------------------------------------
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