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 <[email protected]>
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 ?
>

--





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| c/o: ? SISSA & CNR-INFM Democritos, ? ? ? ? ? ? ?|
| ? ? ? ?via Beirut 2-4, 34014 Trieste (Italy) ? ? |

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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 
P.O.Box 603 ? Beijing 100190
China 


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