In the dipole example file (/lammps/examples/dipole/in.dipole), what does the “update dipole” keyword do in the fix nve/sphere command? I can’t seem to find it in the documentation for nve/sphere or npt/sphere.
Thanks.
In the dipole example file (/lammps/examples/dipole/in.dipole), what does
the "update dipole" keyword do in the fix nve/sphere command? I can't seem
to find it in the documentation for nve/sphere or npt/sphere.
if the documentation doesn't help, there is always the look into the source.
here is what fix_nve_sphere.cpp has to say:
// update mu for dipoles
// d_mu/dt = omega cross mu
// renormalize mu to dipole length
it seems only to be recognised by nve/sphere
axel.
It's on the doc page for fix nve/sphere. It updates the orientation
of the dipole. A similar option would have to be added to
nvt/sphere or npt/sphere.
Steve
I’ll see if I can figure out how to include it in the npt/sphere fix. If so I’ll send you the source.
How hard would it be to update some dipoles and not others? I want to create a dipole layer on a surface interacting with a fluid. Would it just be as simple as having multiple instances of nve/sphere for different groups of atoms (fluid, surface, etc)? I seem to recall you shouldn’t have multiple nve fixes defined.
Dave
All of the integrate fixes work on a group of atoms. You
can have multiple groups and multiple integrate fixes. What
you don't want to do however if have multiple npt fixes, since
each will dilate the box.
Steve