forked from lijiext/lammps
55 lines
1.7 KiB
Plaintext
55 lines
1.7 KiB
Plaintext
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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fix spring/self command :h3
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[Syntax:]
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fix ID group-ID spring/self K :pre
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ID, group-ID are documented in "fix"_fix.html command
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spring/self = style name of this fix command
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K = spring constant (force/distance units) :ul
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[Examples:]
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fix tether boundary-atoms spring/self 10.0 :pre
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[Description:]
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Apply a spring force independently to each atom in the group to tether
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it to its initial position. The initial position for each atom is its
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location at the time the fix command was issued. At each timestep,
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the magnitude of the force on each atom is -Kr, where r is the
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displacement of the atom from its current position to its initial
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position.
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[Restart, fix_modify, output, run start/stop, minimize info:]
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This fix writes the original coordinates of tethered atoms to "binary
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restart files"_restart.html, so that the spring effect will be the
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same in a restarted simulation. See the
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"read_restart"_read_restart.html command for info on how to re-specify
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a fix in an input script that reads a restart file, so that the
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operation of the fix continues in an uninterrupted fashion.
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None of the "fix_modify"_fix_modify.html options are relevant to this
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fix. No global scalar or vector or per-atom quantities are stored by
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this fix for access by various "output
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commands"_Section_howto.html#4_15. No parameter of this fix can be
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used with the {start/stop} keywords of the "run"_run.html command.
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This fix is not invoked during "energy minimization"_minimize.html.
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[Restrictions:] none
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[Related commands:]
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"fix drag"_fix_drag.html, "fix spring"_fix_spring.html
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[Default:] none
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