[lammps-users] PMF calculation


I could really use some help with something basic. I want to do a
potential of mean force calculation above a mineral surface. In the
attached input I have successfully constrained my adsorbing atom to a
plane and fixed one atom of the slab to keep it fixed. I just need to
get the outputted values from fix 3 (planeforce) to average and print to
my output file.

Any advice on what to relpace the commented line with would be much

than you all very much

matthew wander
WSU chemistry

# silia adsorption of Na PMF calculation

units real
dimension 3
boundary p p p
atom_style full

pair_style lj/cut/coul/long 10.97
pair_modify mix arithmetic

bond_style harmonic
angle_style harmonic
dihedral_style none
improper_style none
kspace_style ewald 0.0001

read_data pmf.data

neighbor 2.0 bin
neigh_modify check yes

timestep 1.0
run_style verlet

Not sure what you mean by "outputted values from planeforce".
As the doc page for it states, there are no computed values
it makes available for other commands. However, it would
not be hard to add a bit of code to it (see fix_set_force.cpp
as an example), to have it store the total force on the
group's atoms before the forces are changed. Then
you could access those values via fix ave/time, etc.

But not sure if that's what you're asking.