forked from lijiext/lammps
77 lines
2.3 KiB
Plaintext
77 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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compute basal/atom command :h3
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[Syntax:]
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compute ID group-ID basal/atom :pre
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ID, group-ID are documented in "compute"_compute.html command
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basal/atom = style name of this compute command :ul
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[Examples:]
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compute 1 all basal/atom :pre
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[Description:]
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Defines a computation that calculates the hexagonal close-packed "c"
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lattice vector for each atom in the group. It does this by
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calculating the normal unit vector to the basal plane for each atom.
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The results enable efficient identification and characterization of
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twins and grains in hexagonal close-packed structures.
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The output of the compute is thus the 3 components of a unit vector
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associdate with each atom. The components are set to 0.0 for
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atoms not in the group.
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Details of the calculation are given in "(Barrett)"_#Barrett.
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The neighbor list needed to compute this quantity is constructed each
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time the calculation is performed (i.e. each time a snapshot of atoms
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is dumped). Thus it can be inefficient to compute/dump this quantity
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too frequently or to have multiple compute/dump commands, each of
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which computes this quantity.
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An example input script that uses this compute is provided
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in examples/USER/misc/basal.
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[Output info:]
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This compute calculates a per-atom array with 3 columns, which can be
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accessed by indices 1-3 by any command that uses per-atom values from
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a compute as input. See "Section_howto
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15"_Section_howto.html#howto_15 for an overview of LAMMPS output
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options.
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The per-atom vector values are unitless since the 3 columns represent
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components of a unit vector.
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[Restrictions:]
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This compute is part of the USER-MISC package. It is only enabled if
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LAMMPS was built with that package. See the "Making
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LAMMPS"_Section_start.html#start_3 section for more info.
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The output of this compute will be meaningless unless the atoms are on
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(or near) hcp lattice sites, since the calculation assumes a
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well-defined basal plane.
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[Related commands:]
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"compute centro/atom"_compute_centro_atom.html, "compute
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ackland/atom"_compute_ackland_atom.html
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[Default:] none
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:line
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:link(Barrett)
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[(Barrett)] Barrett, Tschopp, El Kadiri, Scripta Mat. 66, p.666 (2012).
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