[CP2K-user] Geo opt with fixed atoms relative positions

[j...@gmail.com]

Hello,

This method will only work for MD calculations. You can try using a 
restraint (  MOTION / CONSTRAINT / COLLECTIVE / RESTRAINT ) with a high K 
value.

Best,
Julian



ha... at gmail.com schrieb am Dienstag, 15. September 2020 um 03:41:33 
UTC+2:

> Dear users,
>
> I want to optimize the structure with two atoms distance fixed. However 
> the distance between tow atoms (index 44 and 575) still changes during the 
> optimization. 
>
> I know by using "&FIXED_ATOMS" can freeze atoms, but I just want to fix 
> the relative distance between atoms, not *overall atomic position.  *The 
> input is shown below and it only works for MD? Thx!
>
> &GLOBAL
>   ...
>   RUN_TYPE GEO_OPT
>  ...
> &END GLOBAL  
>
> &FORCE_EVAL
> .....
>     &SUBSYS
> .....
>     &COLVAR
>        &DISTANCE
>          ATOMS 44 575
>          AXIS XYZ
>        &END DISTANCE
>     &END COLVAR
>         
>   &END SUBSYS
> &END FORCE_EVAL
>
> &MOTION
>   &GEO_OPT
>     TYPE MINIMIZATION
>     MAX_DR    1.0E-03
>     MAX_FORCE 1.0E-03
>     RMS_DR    1.0E-03
>     RMS_FORCE 1.0E-03
>     MAX_ITER 2000
>     OPTIMIZER BFGS
>   &END GEO_OPT
>
> &CONSTRAINT  
>     &COLLECTIVE
>       COLVAR 1
>       TARGET  xxxx
>       INTERMOLECULAR T
>     &END COLLECTIVE
>   &END CONSTRAINT
>
> &END MOTION
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20200915/642d12af/attachment.htm>