Hello Jelena--

> 
> I am doing water refinement (using Xplor 2.46) for a small metalloprotein, 
> after
> structure calculation using metal restraints in CYANA.
> In my protein, I have the metal cluster which topology I "freeze" in the
> wrefine.py script by fixing metals and binding atoms. 

Is this accomplished using the rigidRegions argument to waterRefineTools.refine?

> The problem I am experiencing is that for certain models I get extremely large
> total energies even though all the models are very similar. 
> For example: 

> XplorPot      VDW       17765.82(80021.66)                     463.3( 80.3)
> 

> Powell::step: irregular exit: Line search abandoned: gradient may be incorrect
> *-- POWELL ------ step=      1 --- stepsize=   0.01000 --- energy evals=    5 
> -*
> |   E(poten)=389918.3302198       grad= 30044.6033617      ANGL=  
> 1619.5106059 |
> |       BOND=  6321.6578947       CDIH=     1.0494587      DIHE=  
> 1028.5803754 |
> |       ELEC=-11596.8057242       HARM=     0.0000000      IMPR=   
> 132.7689804 |
> |        VDW=392361.9271258        noe=    49.6415031                         
>  |
> *------------------------------------------------------------------------------*

It's pretty clear that something is causing problems with the VDW
term. What parameters are you using for the metal ion?

best regards--
Charles

_______________________________________________
Xplor-nih mailing list
[email protected]
https://dcb.cit.nih.gov/mailman/listinfo/xplor-nih

Reply via email to