forked from lijiext/lammps
79 lines
2.7 KiB
Plaintext
79 lines
2.7 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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delete_atoms command :h3
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[Syntax:]
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delete_atoms style args :pre
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style = {group} or {region} or {overlap} :ulb,l
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{group} args = group-ID
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{region} args = region-ID
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{overlap} args = distance type1 type2
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distance = delete atoms with neighbors within this cutoff (distance units)
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type1 = type of first atom in pair (optional)
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type2 = type of other atom in pair (optional)
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:pre
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:ule
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[Examples:]
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delete_atoms group edge
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delete_atoms region sphere
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delete_atoms overlap 0.3
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delete_atoms overlap 0.3 1 1 :pre
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[Description:]
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Delete the specified atoms. This command can be used to carve out
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voids from a block of material or to delete created atoms that are too
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close to each other (e.g. at a grain boundary).
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For style {group}, all atoms belonging to the group are deleted.
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For style {region}, all atoms in the region volume are deleted.
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For style {overlap}, pairs of atoms within the specified cutoff
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distance are searched for, and one of the 2 atoms is deleted. If no
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atom types are specified, an atom will always be deleted if the cutoff
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criterion is met. If a single atom type is specified, then one or
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both of the atoms in the pair must be of the specified type for a
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deletion to occur. If two atom types are specified, the two atoms in
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the pair must be of the specified types for a deletion to occur. For
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a given configuration of atoms, the only guarantee is that at the end
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of the deletion operation, enough deletions will have occurred that no
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atom pairs within the cutoff (and with the specified types) will
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remain. There is no guarantee that the minimum number of atoms will
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be deleted, or that the same atoms will be deleted when running on
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different numbers of processors.
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After atoms are deleted, if the system is not molecular (no bonds),
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then atom IDs are re-assigned so that they run from 1 to the number of
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atoms in the system. This is not done for molecular systems, since it
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would foul up the bond connectivity that has already been assigned.
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[Restrictions:]
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The {overlap} style requires inter-processor communication to acquire
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ghost atoms and setup a neighbor list. This means that your system
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must be ready to perform a simulation before using this command (force
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fields setup, atom masses set, etc).
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If the "special_bonds"_special_bonds.html command is used with a
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setting of 0, then a pair of bonded atoms (1-2, 1-3, or 1-4) will not
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appear in the neighbor list, and thus will not be considered for
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deletion by the {overlap} style. You probably don't want to be
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deleting one atom in a bonded pair anyway.
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[Related commands:]
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"create_atoms"_create_atoms.html
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[Default:] none
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