forked from lijiext/lammps
58 lines
1.6 KiB
Plaintext
58 lines
1.6 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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compute com command :h3
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[Syntax:]
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compute ID group-ID com :pre
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ID, group-ID are documented in "compute"_compute.html command
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com = style name of this compute command :ul
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[Examples:]
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compute 1 all com :pre
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[Description:]
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Define a computation that calculates the center-of-mass of the group
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of atoms, including all effects due to atoms passing thru periodic
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boundaries.
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A vector of three quantites is calculated by this compute, which
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are the x,y,z coordinates of the center of mass.
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IMPORTANT NOTE: The coordinates of an atom contribute to the
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center-of-mass in "unwrapped" form, by using the image flags
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associated with each atom. See the "dump custom"_dump.html command
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for a discussion of "unwrapped" coordinates. See the Atoms section of
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the "read_data"_read_data.html command for a discussion of image flags
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and how they are set for each atom. You can reset the image flags
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(e.g. to 0) before invoking this compute by using the "set
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image"_set.html command.
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[Output info:]
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This compute calculates a global vector of length 3, which can be
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accessed by indices 1-3 by any command that uses global vector values
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from a compute as input. See "this
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section"_Section_howto.html#howto_15 for an overview of LAMMPS output
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options.
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The vector values are "intensive". The vector values will be in
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distance "units"_units.html.
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[Restrictions:] none
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[Related commands:]
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"compute com/molecule"_compute_com_molecule.html
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[Default:] none
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