[Pw_forum] fixed spin moment calculation
yumin qian
yuminqian at gmail.com
Fri Mar 13 03:04:27 CET 2009
thanks for your reply , It is very kind of you
2009/3/12 e kb <eminekb at yahoo.com>
> Dear Yumin Qian,
> You may want to check with another pseudopotential for Oxygen. It might be
> totally unrelated but I've seen this attached in the details part:
>
> Warning: this O psp has been tested in liquid water simulations by
> Patrick Sit and Nicola Marzari. Results for the diffusion coefficient
> and pair correlation functions were at odd with those obtained with
> other ultrasoft or norm-conserving pseudopotentials, and recently
> published result.
>
> Emine Kucukbenli, grad student, SISSA, Italy.
>
> --- On *Thu, 3/12/09, yumin qian <yuminqian at gmail.com>* wrote:
>
> From: yumin qian <yuminqian at gmail.com>
> Subject: Re: [Pw_forum] fixed spin moment calculation
> To: "PWSCF Forum" <pw_forum at pwscf.org>
> Date: Thursday, March 12, 2009, 1:01 PM
>
>
> Sorry for confuse you , After checking the input and output file , I
> found that I also did a LiVO2 crystal calcualtion with the same problem,
> the input file I posted is for LiNiO2 and the output file I posted is for
> LiVO2 , here is the complete input and output file from the
> same calcualtion
>
> &control
> calculation='scf'
> restart_mode='from_scratch' ,
> pseudo_dir = '~/software/espresso-4test/pseudo',
> outdir='outscf'
> nstep=60
> prefix='AFM-type'
> tstress = .true.
> tprnfor = .true.
> wf_collect=.true.
> /
> &system
> ibrav = 0, nat=16 , ntyp= 4,
> ecutwfc = 35.0, ecutrho = 300.0,
> occupations='tetrahedra',
> nspin=2,constrained_magnetization='atomic',lambda=5.0,
> starting_magnetization(1)= 0.0,
> starting_magnetization(2)= 1.8,
> starting_magnetization(3)=-1.8,
> starting_magnetization(4)= 0.0,
> lda_plus_u=.true.
> Hubbard_U(1)=0.0
> Hubbard_U(2)=3.0
> Hubbard_U(3)=3.0
> Hubbard_U(4)=0.0
>
> /
> &electrons
> diagonalization='david',
> conv_thr = 1.0e-7,
> mixing_beta = 0.5,
> /
>
> ATOMIC_SPECIES
> Li 6.914 Li.pbe-n-mt_bw.UPF
> V1 50.9415 V.pbe-n-van.UPF
> V2 50.9415 V.pbe-n-van.UPF
> O 15.9994 O.pbe-van_bm.UPF
> ATOMIC_POSITIONS {crystal}
> Li 0.0000000000000000 0.0000000000000000 0.0
> Li 0.0000000000000000 0.0000000000000000 0.5
> Li 0.5000000000000000 0.5000000000000000 0.0
> Li 0.5000000000000000 0.5000000000000000 0.5
> V1 0.0000000000000000 0.5000000000000000 0.25
> V2 0.0000000000000000 0.5000000000000000 0.75
> V2 0.5000000000000000 0.0000000000000000 0.25
> V1 0.5000000000000000 0.0000000000000000 0.75
> O 0.2354848230051515 0.0000000000000000 0.35287967
> O 0.2354848230051515 0.0000000000000000 0.85287967
> O 0.7354848230051516 0.5000000000000000 0.35287967
> O 0.7354848230051516 0.5000000000000000 0.85287967
> O 0.7645151769948484 0.0000000000000000 0.14712033
> O 0.7645151769948484 0.0000000000000000 0.64712033
> O 0.2645151769948484 0.5000000000000000 0.14712033
> O 0.2645151769948484 0.5000000000000000 0.64712033
> K_POINTS {automatic}
> 8 8 6 1 1 1
> CELL_PARAMETERS (alat)
> 9.903876 0.000000 0.000000
> 0.000000 5.622988 0.000000
> -6.542514 0.000000 20.135790
>
> the output file gives
>
>
> ==============================================================================
> atom number 4 relative position : 0.1697 0.2839 1.0166
> charge : 0.065485
> magnetization : 0.000000
> magnetization/charge: 0.000000
> constrained moment : 0.000000
>
>
> ==============================================================================
>
>
> ==============================================================================
> atom number 5 relative position : -0.1652 0.2839 0.5083
> charge : 2.371448
> magnetization : 1.554551
> magnetization/charge: 0.655528
> constrained moment : 1.800000
>
>
> I also changed lambda from 1 to 5 and the final magnetic moment changed
> from 1.55 to 1.50
> so the parameter lambda seems have no impact on the final magnetic moment,
> there should be something wrong with my calcualtion but I can't spot this
> error.
>
>
> 2009/3/12 Gabriele Sclauzero <sclauzer at sissa.it>
>
>> Dear Yumin Qian,
>>
>> There's something strange in this output. I think that atom number 5
>> should be a Ni
>> one, since you were interested in the magnetization of that species, but
>> then, why is the
>> charge around that atom only about 2.5? Ni should have 10 electrons in
>> valence, so I would
>> expect to get a number around 10 for the charge (unless the atom goes in a
>> very ionized
>> state, but that seems highly unprobable to me).
>> Are you sure PPs and all the rest is OK?
>>
>>
>> GS
>>
>> yumin qian wrote:
>> > thanks for your reply ,I changed the lambda=5.0 and used
>> > occupations='tetrahedra' but the magnetization still did not
>> > converge to the initial value ,but the total energy converged.
>> > I do know what is the problem.
>> >
>> ==============================================================================
>> > > atom number 5 relative position : -0.1652 0.2839
>> 0.5083
>> > > charge : 2.373353
>> > > magnetization : 1.544423
>> > > magnetization/charge: 0.650735
>> > > constrained moment : 1.800000
>> > >
>> > >
>> >
>> ==============================================================================
>> > > the output file gives a magnetic moment of 1.5444 ,how should I
>> do to
>> > > make the calculation converge to the starting_magnetization 1.8
>> ?
>> >
>>
>> --
>>
>>
>> o ------------------------------------------------ o
>> | Gabriele Sclauzero, PhD Student |
>> | c/o: SISSA & CNR-INFM Democritos, |
>> | via Beirut 2-4, 34014 Trieste (Italy) |
>> | email: sclauzer at sissa.it |
>> | phone: +39 040 3787 511 |
>> | skype: gurlonotturno |
>> o ------------------------------------------------ o
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>>
>
>
>
> --
> Sincerely Y. M. Qian
> Lab.of Condensed Matter Theory and Materials Computation
> Institute of Physics
> Chinese Academy of Sciences
> Tel: + 8610 8264 9147
> E-Mail:yuminqian at gmail.com <E-Mail%3Ayuminqian at gmail.com>
> P.O.Box 603 Beijing 100190
> China
>
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--
Sincerely Y. M. Qian
Lab.of Condensed Matter Theory and Materials Computation
Institute of Physics
Chinese Academy of Sciences
Tel: + 8610 8264 9147
E-Mail:yuminqian at gmail.com <E-Mail%3Ayuminqian at gmail.com>
P.O.Box 603 Beijing 100190
China
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