lammps/doc/fix_spring_self.txt

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fix spring/self command :h3

[Syntax:]

fix ID group-ID spring/self K :pre

ID, group-ID are documented in "fix"_fix.html command
spring/self = style name of this fix command
K = spring constant (force/distance units) :ul

[Examples:]

fix tether boundary-atoms spring/self 10.0 :pre

[Description:]

Apply a spring force independently to each atom in the group to tether
it to its initial position.  The initial position for each atom is its
location at the time the fix command was issued.  At each timestep,
the magnitude of the force on each atom is -Kr, where r is the
displacement of the atom from its current position to its initial
position.

[Restart, fix_modify, thermo output, run start/stop, minimize info:]

This fix writes the original coordinates of tethered atoms to "binary
restart files"_restart.html, so that the spring effect will be the
same in a restarted simulation.  See the
"read_restart"_read_restart.html command for info on how to re-specify
a fix in an input script that reads a restart file, so that the
operation of the fix continues in an uninterrupted fashion.

None of the "fix_modify"_fix_modify.html options are relevant to this
fix.  No quantities calculated by this fix can be output by the
"thermo_style custom"_thermo_style.html command.  No parameter of this
fix can be used with the {start/stop} keywords of the "run"_run.html
command.  This fix is not invoked during "energy
minimization"_minimize.html.

[Restrictions:] none

[Related commands:]

"fix drag"_fix_drag.html, "fix spring"_fix_spring.html

[Default:] none