[Pw_forum] Error: bfgs history already reset at previous step

[mohnish pandey]

Dear Vega,
                   Try reducing "trust_radius_min". I faced the same problem
once and I did the same thing and it worked.  Normally this happens near the
convergence...
HAPPY COMPUTING,
MOHNISH,

On Wed, Jan 6, 2010 at 9:11 AM, vega lew <quantumdft at gmail.com> wrote:

> Dear all,
>
> I used to calculate the structure and the energy of  Pt dimers (two Pt
> atoms) in a large supercell. I have tested various structure in triplet,
> which is most stable state for single Pt atom.
> But the code report errors after a few bfgs steps like this:
>
>  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      task #         0
>      from bfgs : error #         1
>      bfgs history already reset at previous step
>
>  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>  I wondering how to deal with this situation.
>
> my input files is shown as follows,
>
>  &CONTROL
>                  calculation = 'relax'
> ,
>                 restart_mode = 'from_scratch'
> ,
>                       outdir = '/tmp/' ,
>                       wfcdir = '/tmp/'
> ,
>                   pseudo_dir = '/home/vega/espresso/pseudo/'
> ,
>                      disk_io = 'none'
> ,
>                        nstep = 1000
> ,
>  /
>
>  &SYSTEM
>
>                        ibrav =
> 8,
>                    celldm(1) =24.8624,
>                    celldm(2) = 0.8520,
>                    celldm(3) = 1.6964,
>                          nat =
> 2,
>                         ntyp =
> 1,
>                        nosym = .true.
> ,
>                    ecutwfc   =   30,
>                    ecutrho   =  300,
>                  occupations = 'smearing',
>                      degauss = 0.007,
>                         nspin = 2,
>                    multiplicity = 3,
>  /
>
>  &ELECTRONS
>
>                  mixing_mode ='local-TF',
>                  mixing_beta =
> 0.4,
>
>  /
>
>  &IONS
>
>                 ion_dynamics = 'bfgs'
> ,
>  /
>
>
> ATOMIC_SPECIES
>     Pt  195.08
> Pt.pw91-n-van.UPF
> ATOMIC_POSITIONS crystal
> Pt       0.540794031   0.322983976   0.495002098
> Pt       0.500777594   0.548429786   0.493029885
> K_POINTS gamma
>
> the input parameters might not very suitable for the calculation of Pt
> dimers itself. But the parameters should be consistent with the previous
> calculation, which is composed of two Pt atoms on certain surface slab
> model.
>
> So could any one give me some suggestions?
>
> Thank you for reading
>
> vega
>
> --
>
> ==================================================================================
> Vega Lew ( weijia liu)
> Graduate student
> State Key Laboratory of Materials-oriented Chemical Engineering
> College of Chemistry and Chemical Engineering
> Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
>
> ******************************************************************************************************************
> Email: vegalew at gmail.com
> Office: Room A705, Technical Innovation Building, Xinmofan Road 5#,
> Nanjing, Jiangsu, China
> ******************************************************************************************************************
>
>
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>
>


-- 
Mohnish Pandey
Y6927262,4th Year dual degree student,
Department of Chemical Engineering,
IIT KANPUR
09235721300
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