Re: [ESPResSo-users] Problem for Zeeman energy and dimension of box

[Rudolf Weeber]

Hi,
On Fri, Apr 26, 2019 at 09:37:43PM +0800, address@hidden wrote:
> I want to simulate the magnetic gels which have polymer and magnetic 
> particles like this paper:
> Weeber, R., Kantorovich, S., & Holm, C. (2012). Deformation mechanisms in 2d 
> magnetic gels studied by computer simulations. Soft Matter, 8(38), 9923-9932.
> 
> And I checked the documentation and didn't found the Zeeman energy. How to 
> simulate the motion of magnetic particles under  the magnetic field?
Please see:
http://espressomd.org/html/doc/_modules/espressomd/constraints.html#HomogeneousMagneticField
which is added to the system via system.constraints.add()
> In addition, I'm confused to simulate the models that are quasi 
> two-dimensional in which the particles are all placed within a plane, 
> however, the dipole moments are free to rotate in 3D.
Please see:
http://espressomd.org/html/doc/running.html#integrating-rotational-degrees-of-freedom
You can confine a particle's motion to the plane via the `fix` property.
You can control around which axes the particle rotates by its `rotation`
property. For a qusi-2D setup
particle.fix = (0,0,1)
particle.rotation = (1,1,1)


Hope that helps.
Regards, Rudolf Weeber

--
Dr. Rudolf Weeber
Institute for Computational Physics
Universität Stuttgart
Allmandring 3
70569 Stuttgart
Germany
Phone: +49(0)711/685-67717
Email: address@hidden
http://www.icp.uni-stuttgart.de/~icp/Rudolf_Weeber