[ESPResSo-users] Simulation of dipole system

[Sreekumari Aparna]

Hello,

Shouldn't I active the feature "ROTATION". In User's Guide its telling to 
active. I have activated all the three features. I am still getting this error  
"" unknown particle parameter "dip" while executing  "part 0 dip $dx $dy $dz 
dipm 1.0 type 0 mass 1.0" "" 

Regards,
Aparna


From: address@hidden address@hidden on behalf of Olaf Lenz address@hidden
Sent: Thursday, July 28, 2011 2:57 PM
To: address@hidden
Subject: Re: [ESPResSo-users] Simulation of dipole system

On 07/28/2011 02:52 PM, Sreekumari Aparna wrote:
> Hello All,
>
> I am a first year graduate student working on dipole system. I want
> to simulate ferrofluids. I have tried to write an input file for
> this purpose. I am getting problems with "dipm" and " part dip"
> commands. I am attaching the input file here. Can some body help me
> rectify the bug in my input file.

Have you activated the features MAGNETOSTATICS and DIPOLES?
If not, do so. Look into the User's Guide to learn how to do that.

Olaf


--
Dr. rer. nat. Olaf Lenz
Institut für Computerphysik, Pfaffenwaldring 27, D-70569 Stuttgart
Phone: +49-711-685-63607

Hi,

On Thu, Jul 28, 2011 at 12:52:05PM +0000, Sreekumari  Aparna wrote:
> Hello All,
> 
> I am a first year graduate student working on dipole system. I want to 
> simulate ferrofluids. I have tried to write an input file for this purpose. I 
> am getting problems with "dipm" and " part dip" commands. I am attaching the 
> input file here. Can some body help me rectify the bug in my input file.
In general, the dipole moment is best set using just dip, i.e.
part 0 dip $dx $dy $dz
Its magnitude can be set by scaling the vector dx,dy,dz.
Currently, in your script, you scale the dipole moment by box_l, which is 
probably not intended.
To draw a random dipole moment which is equally distributed on the unit sphere, 
one can e.g., draw
phi from 0..2*pi
and
cos(theta) from -1..1
and then convert from spherical to carthesian coordinates.

Hope that helps.
Regards, Rudolf