forked from lijiext/lammps
73 lines
2.4 KiB
Plaintext
73 lines
2.4 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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boundary command :h3
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[Syntax:]
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boundary x y z :pre
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x,y,z = {p} or {s} or {f} or {m}, one or two letters :ulb,l
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{p} is periodic
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{f} is non-periodic and fixed
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{s} is non-periodic and shrink-wrapped
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{m} is non-periodic and shrink-wrapped with a minimum value :pre
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:ule
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[Examples:]
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boundary p p f
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boundary p fs p
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boundary s f fm :pre
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[Description:]
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Set the style of boundaries for the global simulation box in each
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dimension. A single letter assigns the same style to both the lower
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and upper face of the box. Two letters assigns the first style to the
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lower face and the second style to the upper face. The initial size
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of the simulation box is set by the "read_data"_read_data.html,
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"read_restart"_read_restart.html, or "create_box"_create_box.html
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commands.
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The style {p} means the box is periodic, so that particles interact
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across the boundary, and they can exit one end of the box and re-enter
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the other end. A periodic dimension can change in size due to
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constant pressure boundary conditions or box deformation (see the "fix
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npt"_fix_nh.html and "fix deform"_fix_deform.html commands). The {p}
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style must be applied to both faces of a dimension.
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The styles {f}, {s}, and {m} mean the box is non-periodic, so that
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particles do not interact across the boundary and do not move from one
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side of the box to the other. For style {f}, the position of the face
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is fixed. If an atom moves outside the face it may be lost. For
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style {s}, the position of the face is set so as to encompass the
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atoms in that dimension (shrink-wrapping), no matter how far they
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move. For style {m}, shrink-wrapping occurs, but is bounded by the
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value specified in the data or restart file or set by the
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"create_box"_create_box.html command. For example, if the upper z
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face has a value of 50.0 in the data file, the face will always be
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positioned at 50.0 or above, even if the maximum z-extent of all the
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atoms becomes less than 50.0.
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[Restrictions:]
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This command cannot be used after the simulation box is defined by a
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"read_data"_read_data.html or "create_box"_create_box.html command.
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For 2d simulations, the z dimension must be periodic.
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[Related commands:]
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See the "thermo_modify"_thermo_modify.html command for a discussion
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of lost atoms.
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[Default:]
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boundary p p p :pre
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