[Pw_forum] Is the constrain card avaible?

[Lorenzo Paulatto]

In data 16 settembre 2009 alle ore 09:55:56, Lu Yunhao <phylyh at nus.edu.sg>  
ha scritto:

> I set the constrains card in input file to constrain the distance between
> two atoms in relaxation, but the it does not work at all. I am not sure
> what's wrong. Is there anyone can help me? Thanks!
> ...
> ion_dynamics = 'bfgs',
> CONSTRAINTS

Dear Lu Yunhao,
unluckily constraints are not implemented with bfgs, they are just  
ignored. I have an experimental version of the code that enforces them,  
but has some problems (constraints can break symmetry, causing the code to  
stop).

If you want I can give you the experimental version for you to try, or you  
can use damped dynamics instead of bfgs.

best regards



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Lorenzo Paulatto
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