forked from lijiext/lammps
69 lines
2.3 KiB
Plaintext
69 lines
2.3 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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create_box command :h3
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[Syntax:]
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create_box N region-ID :pre
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N = # of atom types to use in this simulation
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region-ID = ID of region to use as simulation domain :ul
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[Examples:]
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create_box 2 mybox :pre
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[Description:]
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This command creates a simulation box based on the specified region.
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Thus a "region"_region.html command must first be used to define a
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geometric domain.
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The argument N is the number of atom types that will be used in the
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simulation.
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If the region is not of style {prism}, then LAMMPS encloses the region
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(block, sphere, etc) with an axis-aligned (orthogonal) box which
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becomes the simulation domain.
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If the region is of style {prism}, LAMMPS creates a non-orthogonal
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simulation domain shaped as a parallelepiped with triclinic symmetry.
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See the "region prism"_region.html command for a description of how
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the shape of the parallelepiped is defined. The parallelepiped has
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its "origin" at (xlo,ylo,zlo) and 3 edge vectors starting from its
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origin given by a = (xhi-xlo,0,0); b = (xy,yhi-ylo,0); c =
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(xz,yz,zhi-zlo).
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A prism region used with the create_box command must have tilt factors
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(xy,xz,yz) that do not skew the box more than half the distance of the
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parallel box length. For example, if xlo = 2 and xhi = 12, then the x
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box length is 10 and the xy tilt factor must be between -5 and 5.
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Similarly, both xz and yz must be between -(xhi-xlo)/2 and
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+(yhi-ylo)/2. Note that this is not a limitation, since if the
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maximum tilt factor is 5 (as in this example), then configurations
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with tilt = ..., -15, -5, 5, 15, 25, ... are all equivalent.
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When a prism region is used, the simulation domain must be periodic in
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any dimensions with a non-zero tilt factor, as defined by the
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"boundary"_boundary.html command. I.e. if the xy tilt factor is
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non-zero, then both the x and y dimensions must be periodic.
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Similarly, x and z must be periodic if xz is non-zero and y and z must
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be periodic if yz is non-zero.
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[Restrictions:]
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An "atom_style"_atom_style.html and "region"_region.html must have
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been previously defined to use this command.
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[Related commands:]
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"create_atoms"_create_atoms.html, "region"_region.html
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[Default:] none
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