forked from lijiext/lammps
58 lines
1.8 KiB
Plaintext
58 lines
1.8 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 wall/reflect command :h3
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[Syntax:]
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fix ID group-ID wall/reflect keyword ... :pre
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ID, group-ID are documented in "fix"_fix.html command
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wall/reflect = style name of this fix command
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one or more keyword/value pairs may be appended to the args
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keyword = {xlo} or {xhi} or {ylo} or {yhi} or {zlo} or {zhi} :ul
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[Examples:]
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fix xwalls all wall/reflect xlo xhi
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fix walls all wall/reflect xlo ylo zlo xhi yhi zhi :pre
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[Description:]
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Bound the simulation with one or more walls which reflect particles
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when they attempt to move thru them.
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Reflection means that if an atom moves outside the box on a timestep
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by a distance delta (e.g. due to "fix nve"_fix_nve.html), then it is
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put back inside the box by the same delta and the sign of the
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corresponding component of its velocity is flipped.
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IMPORTANT NOTE: This fix performs its operations at the same point in
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the timestep as other time integration fixes, such as "fix
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nve"_fix_nve.html, "fix nvt"_fix_nvt.html, or "fix npt"_fix_npt.html.
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Thus fix wall/reflect should normally be the last such fix specified
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in the input script, since the adjustments it makes to atom
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coordinates should come after the changes made by time integration.
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LAMMPS will warn you if your fixes are not ordered this way.
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[Restrictions:]
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Any dimension (xyz) that has a reflecting wall must be non-periodic.
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A reflecting wall cannot be used with rigid bodies such as those
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defined by a "fix rigid" command. This is because the wall/reflect
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displaces atoms directly rather than exerts a force on them. For
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rigid bodies, use a soft wall instead, such as "fix
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wall/lj93"_fix_wall_lj93.html.
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[Related commands:]
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"fix wall/lj93"_fix_wall_lj93.html command
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[Default:] none
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