[ESPResSo-users] OIF - background_errors 0

[Wink, Markus]

Dear ESPResSo-community,

 

I have got a question concerning the OIF implementation. In my case I have put an object (a sphere) in a microfluidic channel that has a rhomboid as a barrier inside. I applied a constant force density to achieve a fluid flow. I want to investigate the trajectory of the object inside the channel. As it reaches the rhomboid, the object is deflected by it. Nevertheless, I get an error message after some time the object is in contact with the rhomboid:

 

background_errors 0 {063 rhomboid constraint 4 violated by particle 376}

 

My interpretation is, that one node of my object (particle 376) tries to enters the rhomboid. That of cause should not be the case.

 

The rhomboid was defined by the command:

 

constraint rhomboid corner $corX $corY $corZ a $aX $aY $aZ b $bX $bY $bZ c $cX $cY $cZ direction 1 type 10

lbboundary rhomboid corner $corX $corY $corZ a $aX $aY $aZ b $bX $bY $bZ c $cX $cY $cZ direction 1

 

 

The object is defined by:

 

oif_add_object object-id 0 template-id 0 origin 125 85 9 part-type 0 mass 1

 

The object-rhomboid interaction is implemented by:

 

inter 0 10 soft-sphere 0.0001 1.2 0.1 0.0

 

How can I avoid the error message mentioned above? Is there any mistake in my script? Does it help to lower the time step (so far, I chose time_step 0.1)?

 

Thanks for your help?

 

Greetings

 

Markus Wink