[Pw_forum] Wrong effective charges in AFM insulator using "zue"
xirainbow
nkxirainbow at gmail.com
Wed Jan 19 10:37:30 CET 2011
Dear professor Andrea Dal Corso:
Thank you for you quickly reply.
I follow your suggestion in scf calculation and add *noncolin= .TRUE.“*with
*occupations = 'fixed'*
The calculated *absolute magnetization = 0.01 Bohr mag/cell *in scf
output.
However in LSDA+smearing calculation, *absolute magnetization =
5.68Bohr mag/cell
*.
The following is my scf.in. Is there anything wrong?
Thank you very much:)
&CONTROL
calculation = 'scf'
title = 'G-10-scf'
verbosity = 'high'
restart_mode = 'from_scratch'
wf_collect = .FALSE.
tstress = .TRUE.
tprnfor = .TRUE.
prefix = 'G-10-scf'
etot_conv_thr = 1.0e-4
forc_conv_thr = 1.0e-3
disk_io = 'low'
pseudo_dir = '~/espresso-4.2.1/pseudo'
/
&SYSTEM
ibrav = 2
celldm = 14.20419765 !bohr
nat = 10
ntyp = 4
ecutwfc = 70
ecutrho = 560
nbnd = 100
nosym = .FALSE.
occupations = 'fixed'
noncolin = .TRUE.
/
&ELECTRONS
electron_maxstep = 100
conv_thr = 1.0e-7
mixing_mode = 'plain'
mixing_beta = 0.7
mixing_ndim = 8
diagonalization = 'david'
diago_david_ndim = 4
/
ATOMIC_SPECIES
Mn1 55 Mn.pbe-sp-van.UPF
Mn2 55 Mn.pbe-sp-van.UPF
Ca 40 Ca.pbe-nsp-van.UPF
O 16 O.pbe-rrkjus.UPF
ATOMIC_POSITIONS {crystal}
Mn1 0.00 0.00 0.00
Mn2 0.50 0.50 0.50
Ca 0.25 0.25 0.25
Ca 0.75 0.75 0.75
O 0.75 0.25 0.75
O 0.25 0.75 0.25
O 0.75 0.75 0.25
O 0.25 0.25 0.75
O 0.25 0.75 0.75
O 0.75 0.25 0.25
K_POINTS {automatic}
6 6 6 0 0 0
On Wed, Jan 19, 2011 at 4:41 PM, Andrea Dal Corso <dalcorso at sissa.it> wrote:
>
> On Wed, 2011-01-19 at 16:27 +0800, xirainbow wrote:
> > In 4.2.1 manual, it is said that:If .zue=true.is an alternative
> > algorithm, different from the default one (if trans .and. epsil ) The
> > results should be the same within numerical noise.
> >
> >
> > However, I get wrong "effective charges" in zue=true in AFM insulator
> > CaMnO3 with 4.2.1
> > These two Mn atoms are the same except antiparallel spin.
> > In "epsil+trans", effective charges of Mn1=7.79, Mn2=7.78;
> > In "zue" , effective charges of Mn1=3.1, Mn2=51.2;
> >
> >
> > I will describe my calculation procedure using 4.2.1 in short.
> > 1: I do scf calculation in scf.in
> > restart_mode = 'from_scratch'
> > occupations = 'smearing'
> > smearing = 'gauss'
> > degauss = 0.002
> > starting_magnetization(1) = 1
> > starting_magnetization(2) = -1
> > starting_magnetization(3) = 0
> > starting_magnetization(4) = 0
> >
> >
> > 2: I do a scf calculation in scf.in
> > restart_mode = 'restart'
> > occupations = 'fixed'
> > nspin = 2
> > tot_magnetization = 0
> >
> >
> > 3: I do ph calculation with
> > zue = .TRUE. !the same with epsil and trans = TRUE
> > (In this condition, effective charges of Mn1=3.1, Mn2=51.2;)
> > or with:
> > epsil = .TRUE. , trans = .TRUE.
> > (In this condition , effective charges of Mn1=7.79, Mn2=7.78;)
> >
> >
> > (The reason is why I restart scf is below:
> > "starting_magnetization" must be used with "smearing". However,
> > "smearing" will give a metal result. Effective charges can not be
> > calculated for metal. But, CaMnO3 is really a insulator AFM.
> > "occupations=fixed" can get a insulator result. However it must used
> > with "tot_magnetization". If I use "tot_magnetization=0", I will get a
> > PM no AFM state.
> > In the end, I use "smearing"+"starting_magnetization" to get a AFM
> > metal. Then I use "fixed"+"tot_magnetization" to get a AFM insulator.
> > Is there any other good method to get a AFM insulator?)
>
> >
> >
> >
> > The following my script for "zue= .TRUE "
> > And I have attached output file of "zue= .TRUE " in accessary.
> > Thanks:)
>
> The phonon with LSDA + constraint is not programmed. So it will not
> work. If the AFM insulator is the ground state then you should obtain it
> with noncolin=.true. without constraint. In this case ph.x at gamma
> should work and you should get the correct effective charges. If not
> please provide the complete input.
>
> HTH,
>
> Andrea
>
>
>
> >
> > #*********************************************
> > # scf-antimag-smearing
> > cat>scf.in<<EOF
> > for vc-relax
> > &CONTROL
> > calculation = 'scf'
> > title = 'G-10-scf'
> > verbosity = 'high'
> > restart_mode = 'from_scratch'
> > wf_collect = .FALSE.
> > tstress = .TRUE.
> > tprnfor = .TRUE.
> > prefix = 'G-10-scf'
> > etot_conv_thr = 1.0e-4
> > forc_conv_thr = 1.0e-3
> > disk_io = 'low'
> > pseudo_dir = './'
> > /
> >
> >
> > &SYSTEM
> > ibrav = 2
> > celldm = 14.20419765
> > nat = 10
> > ntyp = 4
> > nbnd = 50
> > ecutwfc = 70
> > ecutrho = 560
> > nosym = .FALSE.
> > !nosym_evc = .TRUE.
> > !noinv = .TRUE.
> > occupations = 'smearing'
> > smearing = 'gauss'
> > degauss = 0.002
> > starting_magnetization(1) = 1
> > starting_magnetization(2) = -1
> > starting_magnetization(3) = 0
> > starting_magnetization(4) = 0
> > !occupations = 'fixed'
> > nspin = 2
> > !tot_magnetization = 0
> > /
> >
> >
> > &ELECTRONS
> > electron_maxstep = 100
> > conv_thr = 1.0e-7
> > mixing_mode = 'plain'
> > mixing_beta = 0.7
> > mixing_ndim = 8
> > diagonalization = 'david'
> > diago_david_ndim = 4
> > /
> >
> >
> > ATOMIC_SPECIES
> > Mn1 55 Mn.pbe-sp-van.UPF
> > Mn2 55 Mn.pbe-sp-van.UPF
> > Ca 40 Ca.pbe-nsp-van.UPF
> > O 16 O.pbe-rrkjus.UPF
> >
> >
> > ATOMIC_POSITIONS {crystal}
> > Mn1 0.00 0.00 0.00
> > Mn2 0.50 0.50 0.50
> > Ca 0.25 0.25 0.25
> > Ca 0.75 0.75 0.75
> > O 0.75 0.25 0.75
> > O 0.25 0.75 0.25
> > O 0.75 0.75 0.25
> > O 0.25 0.25 0.75
> > O 0.25 0.75 0.75
> > O 0.75 0.25 0.25
> >
> >
> >
> > K_POINTS {automatic}
> > 6 6 6 0 0 0
> > EOF
> > ./dopw <scf.in >G-scf-10-smearing.out
> >
> >
> > # scf-antimag-insulator
> > cat>scf.in<<EOF
> > for vc-relax
> > &CONTROL
> > calculation = 'scf'
> > title = 'G-10-scf'
> > verbosity = 'high'
> > restart_mode = 'restart'
> > wf_collect = .FALSE.
> > tstress = .TRUE.
> > tprnfor = .TRUE.
> > prefix = 'G-10-scf'
> > etot_conv_thr = 1.0e-4
> > forc_conv_thr = 1.0e-3
> > disk_io = 'low'
> > pseudo_dir = './'
> > /
> >
> >
> > &SYSTEM
> > ibrav = 2
> > celldm = ${lattic_parameter} !bohr
> > nat = 10
> > ntyp = 4
> > nbnd = 50
> > ecutwfc = 70
> > ecutrho = 560
> > nosym = .FALSE.
> > !nosym_evc = .TRUE.
> > !noinv = .TRUE.
> > !occupations = 'smearing'
> > !smearing = 'gauss'
> > !degauss = 0.002
> > !starting_magnetization(1) = 1
> > !starting_magnetization(2) = -1
> > !starting_magnetization(3) = 0
> > !starting_magnetization(4) = 0
> > occupations = 'fixed'
> > nspin = 2
> > tot_magnetization = 0
> > /
> >
> >
> > &ELECTRONS
> > electron_maxstep = 100
> > conv_thr = 1.0e-7
> > mixing_mode = 'plain'
> > mixing_beta = 0.7
> > mixing_ndim = 8
> > diagonalization = 'david'
> > diago_david_ndim = 4
> > /
> >
> >
> > ATOMIC_SPECIES
> > Mn1 55 Mn.pbe-sp-van.UPF
> > Mn2 55 Mn.pbe-sp-van.UPF
> > Ca 40 Ca.pbe-nsp-van.UPF
> > O 16 O.pbe-rrkjus.UPF
> >
> >
> > ATOMIC_POSITIONS {crystal}
> > Mn1 0.00 0.00 0.00
> > Mn2 0.50 0.50 0.50
> > Ca 0.25 0.25 0.25
> > Ca 0.75 0.75 0.75
> > O 0.75 0.25 0.75
> > O 0.25 0.75 0.25
> > O 0.75 0.75 0.25
> > O 0.25 0.25 0.75
> > O 0.25 0.75 0.75
> > O 0.75 0.25 0.25
> >
> >
> >
> > K_POINTS {automatic}
> > 6 6 6 0 0 0
> > EOF
> > ./dopw <scf.in >G-scf-10-insulator.out
> >
> >
> > #for phonon-antimag
> > cat>ph.in <<EOF
> > for phonon
> > &INPUTPH
> > amass(1) = 55
> > amass(2) = 55
> > amass(3) = 40
> > amass(4) = 16
> > outdir = "./"
> > prefix = 'G-10-scf' !must be the same with scf
> > ldisp = .FALSE.
> > niter_ph = 100
> > tr2_ph = 1.0e-12
> > alpha_mix(1)= 0.7
> > nmix_ph = 4
> > iverbosity = 1
> > fildyn = 'matdyn'
> > !epsil = .TRUE. !Do not set epsil to .true. for metallic system
> > or q/=0
> > !trans = .TRUE. !if trans .and. epsil effective charges are
> > calculated
> > zue = .TRUE. !the same with epsil and trans = TRUE
> > /
> > 0.0 0.0 0.0
> > EOF
> >
> >
> > ./doph <ph.in >G-ph-10.out
> > done
> > #*********************************************
> >
> > --
> > ____________________________________
> > Hui Wang
> > School of physics, Fudan University, Shanghai, China
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> --
> Andrea Dal Corso Tel. 0039-040-3787428
> SISSA, Via Bonomea 265 Fax. 0039-040-3787249
> I-34136 Trieste (Italy) e-mail: dalcorso at sissa.it
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
--
____________________________________
Hui Wang
School of physics, Fudan University, Shanghai, China
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