Dear lammps developers,
I am studying to use lammps to model polyelectrolyte (coarse-grain model) in solution. The solvents are treated implicitly. I read from many references that the Bjerrum length (lB=e^2/epsilon kB T) is an important parameter to model electrostatic interactions between charged beads. The problem is I don’t know how to set Bjerrum length in the input file of lammps? There seems no such a parameter in lammps. Can you please explain this question clearly? Or can you kindly send me an input file including the Bjerrum length??
Dear lammps developers,
I am studying to use lammps to model polyelectrolyte (coarse-grain
model) in solution. The solvents are treated implicitly. I read from many
references that the Bjerrum length (lB=e^2/epsilon kB T) is an important
parameter to model electrostatic interactions between charged beads. The
problem is I don't know how to set Bjerrum length in the input file of
lammps? There seems no such a parameter in lammps. Can you please explain
there is no such parameters, so you cannot set it
and nobody can explain it. if *you* want to use this
and *you* don't know how it works, then it is *your*
task to figure it out and explain it to others, so they
can help you implementing it. sorry, but life is tough...
this question clearly? Or can you kindly send me an input file including the
Bjerrum length??
the closest thing to what you describe would be a model that
was added to LAMMPS last week. i suggest you read the documentation, http://lammps.sandia.gov/doc/pair_coul_diel.html
and especially papers referenced in it and then check out the
(USER/gauss-diel) example that is bundled with the latest
LAMMPS distribution.
You forgot a factor 1/(4pi) in the formula, but here you are: for a
given temperature, the Bjerrum length is directly related to the
dielectric constant of your implicit solvent, so you just have to
adjust it:
You can also look at papers on the LAMMPS publications page
that discuss polyelectrolytes. I imagine many of them discuss
the Bjerrum length and its meaning in an MD simulation, The
1998 paper by Mark Stevens does for sure.
