forked from lijiext/lammps
44 lines
1.1 KiB
HTML
44 lines
1.1 KiB
HTML
<HTML>
|
|
<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
|
|
</CENTER>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<HR>
|
|
|
|
<H3>fix spring/self command
|
|
</H3>
|
|
<P><B>Syntax:</B>
|
|
</P>
|
|
<PRE>fix ID group-ID spring/self K
|
|
</PRE>
|
|
<UL><LI>ID, group-ID are documented in <A HREF = "fix.html">fix</A> command
|
|
<LI>spring/self = style name of this fix command
|
|
<LI>K = spring constant (force/distance units)
|
|
</UL>
|
|
<P><B>Examples:</B>
|
|
</P>
|
|
<PRE>fix tether boundary-atoms spring/self 10.0
|
|
</PRE>
|
|
<P><B>Description:</B>
|
|
</P>
|
|
<P>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.
|
|
</P>
|
|
<P><B>Restrictions:</B> none
|
|
</P>
|
|
<P><B>Related commands:</B>
|
|
</P>
|
|
<P><A HREF = "fix_drag.html">fix drag</A>, <A HREF = "fix_spring.html">fix spring</A>
|
|
</P>
|
|
<P><B>Default:</B> none
|
|
</P>
|
|
</HTML>
|