[lammps-users] add magnetic field

Dear all,

dear xiaojing,

     First, thank the members of the mail list for providing lots help
to me.

I want to add magnetic field in my system. I just wonder if the lampps
can do it? I believe lampps can. However, could anyone give me some
suggestions to do it?

as usual, it would make it _much_ easier to give recommendations
if you would not only state what you want to do, but rather what
process, system or environment you want to model. whether you can
do something, depends very much on the model and whether an applicable
model does actually exist.

i don't think that lammps can do this out of the box, but you can
certainly implement a "fix" for a magnetic field acting on charged
particles. how difficult this is going to be depends on type of
magnetic field and what kind of system you are looking at. if you are
looking for the effect of a homogeneous static B field on (moving)
charged particles, that should be easy. you can have a look at the
efield fix as an example. unlike the force of the homogeneous E fiel,
F = q times E, you'd have to implement F = q times (v cross B).

if your particles are going to carry a fixed (ferro)magnetic moment
by themselves, it is going to be more complicated. you could consider
using the point dipole interactions as a starting point (pair_style
dipole/cut), but you'd have to implement a new pair_style and the fix.

if you want to go beyond that, you have to consider quantum chemistry
and then it is going to be very complicated...