[Pw_forum] problems on optimization

[Stefano Baroni]

atomic relaxation is allowed in any directions. when some components  
of the forces vanish exactly, this occurs because of symmetry reasons.  
SB

On Mar 26, 2008, at 7:14 PM, Jun Dai wrote:

> Dear PWSCF users,
> i found the forces acting on atoms in the output of the relax  
> examples in
> cvs-version(~/espresso4.0cvs/tests/relax2.out for example) go as  
> follows:
>
>     Forces acting on atoms (Ry/au):
>
>     atom   1 type  1   force =     0.00000000    0.00000000     
> 0.01010485
>     atom   2 type  1   force =     0.00000000    0.00000000    
> -0.00112292
>     atom   3 type  1   force =     0.00000000    0.00000000     
> 0.00257324
>     atom   4 type  1   force =     0.00000000    0.00000000     
> 0.00000000
>     atom   5 type  1   force =     0.00000000    0.00000000    
> -0.00257324
>     atom   6 type  1   force =     0.00000000    0.00000000     
> 0.00112292
>     atom   7 type  1   force =     0.00000000    0.00000000    
> -0.01010485
>
> only forces on z-direction are there, i think maybe relax atoms in  
> all directions
> is more reasonable, is this situation a particular one or a common  
> one?
>
>
>
>
> ------------------------------
> Best regards,
> Jun Dai
>
> =============================================================
> J. Dai
> Ph.D. Candidate,
> Hefei National Laboratory For Physical Sciences at the Microscale,
> University of Science and Technology of China,
> Hefei, Anhui, 230026,
> People's Republic of China
> Tel.: 86-551-3606428
> Fax.: 86-551-3602969
> E-mail: jdai3 at mail.ustc.edu.cn
> =============================================================
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---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center -  
Trieste
[+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype)

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