The ABINIT Users Mailing List ( CLOSED )

[Josef Zwanziger <jzwanzig@dal.ca>]

nstep is the number of steps allowed in the scf cycle for a given geometry, 
ntime is the number of shape-changing steps allowed in the geometry 
optimization. You have ntime set to 5, probably that isn't enough. You might 
try increasing ntime considerably (say to 25 or 30) and see if force 
convergence is improving.


On Thursday 24 April 2008 13:33, pratik_8mar@yahoo.com wrote:
> Dear abinit users
>        i am trying to optimize the cluster of cd4S6. As a starting point i
> took interatomic distance and interbond angle as that of bulk structure. i
> have taken K.E cut off about 70 Ry. and box dimension 30 X 30 X 30 atomic
> units. for nstep equal to 200 also i am not able to reach convergance of
> force of the order of 10E-5 even. here i am sending my input file. i have
> used
> Trouiller-Martins-type, GGA Perdew/Burke/Ernzerhof pseudopotential. so
> please let me know where i might have made mistake that is not letting it
> converge .
>
>  acell 30 30 30
>  rprim        1 0 0 0 1 0 0 0 1
>  ntypat 2
>  znucl 16 48
>  typat        2 6*1 3*2
> xangst
> 1.4542761005 1.4542820399 1.4542761005
> 2.9065216564 2.9065292660 -0.0020529726
> 2.9065216564 2.9065292660 5.8188963462
> 2.9065256163 -0.0020411016 2.9065253141
> 2.9065256163 5.8189082172 2.9065253141
> -0.0020532748 2.9065295676 2.9065216564
> 5.8188960440 2.9065295676 2.9065216564
> 4.3607977564 4.3608113059 1.4522231278
> 4.3608017167 1.4522409389 4.3608014140
> 1.4522228257 4.3608116081 4.3607977564
>
> natom 10
>  diemac 12
> toldff 5.0d-4
> ionmov 7
>  ecut  900 ev
>   iscf 7
> nstep 100
> ixc 11
> kptopt 0
> nkpt 1
> kpt 0 0 0
> ntime 5
> nsym 1
> chkprim 0
>
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-- 
Josef W. Zwanziger
Canada Research Chair in NMR Studies of Materials
Director, Atlantic Region Magnetic Resonance Centre
Dept. of Chemistry and Inst. for Research in Materials
Dalhousie University
Halifax B3H 4J3 Canada
+1 (902) 494-1960
jzwanzig@dal.ca
http://jwz.chem.dal.ca

On sabbatical January-July 2008
Max Planck Institute for Polymer Research
Mainz, Germany