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

[vega lew]

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
******************************************************************************************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20100106/44473d7c/attachment.html>