QMMM: Does QM periodic in XYZ require mandatory WALLS in my case?

[ganta.pra... at gmail.com]

Dear CP2K team/users,

I am trying to do QMMM simulations and I am trying to use periodic QM which 
is the same size as the MM box (i.e QM=MM size). I ran the QMMM simulation 
and I get this error:

 *** WARNING in qmmm_util.F:197 :: One or few QM atoms are within the SKIN 
***
 *** of the quantum box. Check your run and you may possibly consider: the 
***
 *** activation of the QMMM WALLS around the QM box, switching ON the      
***
 *** centering of the QM box or increase the size of the QM cell. CP2K    
 ***
 *** CONTINUE but results could be meaningless.                            
***

Is it mandatory that I should use QM Walls when QM box is periodic? or can 
I ignore the error this error?

I am also planning to do QM periodic in XY only (not xyz) case. 

My system is a mineral surface+phospahte on the top+surrounded by water. QM 
part: Mineral (top layer)+phosphate+water(some part) MM part: Mineral 
(bottom layer) + water (some part)

<https://lh3.googleusercontent.com/-OHStR5e4pik/WsN2LqrssRI/AAAAAAAADsM/ITimathrrrAGO8XyObZqr8ilDAq5NqZ2gCLcBGAs/s1600/ads_gimp.png>




Have a nice day.


Thank you in advance. 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20180403/27314f7d/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: input_qmmm_SPCE.inp
Type: chemical/x-gamess-input
Size: 8521 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20180403/27314f7d/attachment.inp>