[Wien] about optimize the hexagonal cell .the force is increasing.

[Mary White]

Dear users,
        I use PORT option to optimize the hexagonal structure including cell parameters and atom position. But the force on an atom is too big ,as follows.

:FGL001:   1.ATOM               -57.904000127     0.000000127     0.000000000
:FGL001:   1.ATOM               -59.863000131     0.000000131     0.000000000
:FGL001:   1.ATOM               -68.146000149     0.000000149     0.000000000

:FGL002:   2.ATOM               -32.135000070     0.000000070     0.000000000
:FGL002:   2.ATOM               -31.330000068     0.000000068     0.000000000
:FGL002:   2.ATOM               -28.205000062     0.000000062     0.000000000

:ENE  : ********** TOTAL ENERGY IN Ry =      -158751.858644
:ENE  : ********** TOTAL ENERGY IN Ry =      -158751.860470
:ENE  : ********** TOTAL ENERGY IN Ry =      -158751.867677


The force on atom1 is increasing. I have decreased the delta in case.inM. This file 
is as follows:
PORT 2.0 0.20      # PORT/NEWT;  tolf, Initial Trust Radius
0.2 0.0 0.0 1.0   #Atom  1 Generated by pairhess
0.2 0.0 0.0 1.0   #Atom  2 Generated by pairhess

     The force is still increasing. And 
 " :WARNING, CURVATURE CONDITION FAILED
 :WARNING, S.Y WAS -1.050783136317473E-005
 :WARNING, CURVATURE CONDITION FAILED
 :WARNING, S.Y WAS -1.872153352633030E-004 " is appear.
I don't know how to deal with this case.
If any one know about this,please give some suggestion.Any comments will be appreciated. 
Thank you in advance.
                                                                                     Mary



       
---------------------------------
Fussy? Opinionated? Impossible to please? Perfect.  Join Yahoo!'s user panel and lay it on us.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20070727/c5440657/attachment.html