[Pw_forum] Question on SCF

[Paolo Giannozzi]

On Fri, 2014-01-24 at 13:58 +0000, Hadi Arefi wrote:
> celldm(1) = 0 ??!! In any choice of ibra, Celldm cannot be zero!

it can, if ibrav=0. In that case, the length of the first lattice
vector is the lattice parameter.

P.

>  
> 
>  
> 
> From: pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org]
> On Behalf Of Heng Luo
> Sent: 23 January 2014 21:05
> To: pw_forum at pwscf.org
> Subject: [Pw_forum] Question on SCF
> 
>  
> 
> To whom it concerns,
> 
> 
>  
> 
> 
> I am trying to use QuantumEspresso to do some geometry optimization
> calculations. But my self-consistency does not converge. I have tried
> your ideas in the official site, but it is still not working. Can you
> give me some suggestion?
> 
> 
>  
> 
> 
> Here is my input data:
> 
> 
>  
> 
> 
> &control
> 
>   calculation       = 'vc-relax'
> 
>   pseudo_dir        = '/home/frankhen/espresso/pseudo/'
> 
>   restart_mode      = 'from_scratch'
> 
>   prefix            = 'sto',
> 
>   verbosity         = 'high',
> 
> /
> 
> &system
> 
>   ibrav              = 0
> 
>   celldm(1)          = 0
> 
>   nat                = 39,
> 
>   ntyp               = 5,
> 
>   ecutwfc            = 25.0,
> 
>   ecutrho            = 250.0,
> 
>   occupations        = 'smearing',
> 
>   degauss            = 0.05,
> 
> /
> 
> &electrons
> 
>   conv_thr           = 1.D-4,
> 
>   electron_maxstep   = 10000,
> 
>   mixing_beta = 0.3,
> 
>   diagonalization = 'cg',
> 
> /
> 
> &ions
> 
> /
> 
> &CELL
> 
>    cell_dynamics = 'damp-w' ,
> 
>    press = 0.00 ,
> 
>    wmass =  0.00700000
> 
>  /
> 
> ATOMIC_SPECIES
> 
>   Fe     55.85       Fe.pbe-sp-van_ak.UPF
> 
>   Co     58.93       Co.pbe-sp-van.UPF
> 
>   La     138.91      La.pbe-nsp-van.UPF
> 
>   Sr     87.62       Sr.pbe-nsp-van.UPF
> 
>   O      15.9994     O.pbe-van_ak.UPF
> 
> ATOMIC_POSITIONS
> 
> Fe 0.5 0 0 1 1 1
> 
> Fe 0 0.5 0 1 1 1
> 
> Fe 0 0 0.5 1 1 1
> 
> Fe 0 0.5 0.5 1 1 1
> 
> Fe 0.5 0 0.5 1 1 1
> 
> Fe 0.5 0.5 0 1 1 1
> 
> Co 0 0 0 1 1 1
> 
> Co 0.5 0.5 0.5 1 1 1
> 
> La 0.25 0.25 0.25 1 1 1
> 
> La 0.25 0.75 0.25 1 1 1
> 
> La 0.25 0.25 0.75 1 1 1
> 
> La 0.75 0.25 0.75 1 1 1
> 
> La 0.75 0.75 0.25 1 1 1
> 
> La 0.75 0.75 0.75 1 1 1
> 
> Sr 0.75 0.25 0.25 1 1 1
> 
> Sr 0.25 0.75 0.75 1 1 1
> 
> O 0 0.25 0 1 1 1
> 
> O 0 0 0.25 1 1 1
> 
> O 0.75 0 0 1 1 1
> 
> O 0.5 0.25 0 1 1 1
> 
> O 0.5 0 0.25 1 1 1
> 
> O 0.25 0.5 0 1 1 1
> 
> O 0 0.75 0 1 1 1
> 
> O 0 0.5 0.25 1 1 1
> 
> O 0.25 0 0.5 1 1 1
> 
> O 0 0.25 0.5 1 1 1
> 
> O 0 0 0.75 1 1 1
> 
> O 0.25 0.5 0.5 1 1 1
> 
> O 0 0.75 0.5 1 1 1
> 
> O 0 0.5 0.75 1 1 1
> 
> O 0.75 0 0.5 1 1 1
> 
> O 0.5 0.25 0.5 1 1 1
> 
> O 0.5 0 0.75 1 1 1
> 
> O 0.75 0.5 0 1 1 1
> 
> O 0.5 0.75 0 1 1 1
> 
> O 0.5 0.5 0.25 1 1 1
> 
> O 0.75 0.5 0.5 1 1 1
> 
> O 0.5 0.75 0.5 1 1 1
> 
> O 0.5 0.5 0.75 1 1 1
> 
> K_POINTS {automatic}
> 
>   2 2 2  0 0 0
> 
> CELL_PARAMETERS {angstrom}
> 
> 14.74 0.0 0.0
> 
> 0.0 14.74 0.0
> 
> 0.0 0.0 14.74
> 
>  
> 
> Sincerely,
> 
> Heng
> 
> 
>  
> 
> 
> -- 
> 
> Heng Luo
> 
> Ph.D candidate
> 
> 
> Department of Mechanical Engineering
> 
> 
> 15 Saint Mary's Street, Room 122
> 
> 
> Brookline, Ma 02446
> 
> 
> Boston University
> 
> 
>  
> 
> 
> Office: 617-353-8469
> 
> 
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-- 
 Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
 Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
 Phone +39-0432-558216, fax +39-0432-558222