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lammps/doc/src/compute_ackland_atom.txt
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compute_ackland_atom.txt
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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)
:line
compute ackland/atom command :h3
[Syntax:]
compute ID group-ID ackland/atom :pre
ID, group-ID are documented in "compute"_compute.html command
ackland/atom = style name of this compute command :ul
[Examples:]
compute 1 all ackland/atom :pre
[Description:]
Defines a computation that calculates the local lattice structure
according to the formulation given in "(Ackland)"_#Ackland.
In contrast to the "centro-symmetry
parameter"_compute_centro_atom.html this method is stable against
temperature boost, because it is based not on the distance between
particles but the angles. Therefore statistical fluctuations are
averaged out a little more. A comparison with the Common Neighbor
Analysis metric is made in the paper.
The result is a number which is mapped to the following different
lattice structures:
0 = UNKNOWN
1 = BCC
2 = FCC
3 = HCP
4 = ICO :ul
The neighbor list needed to compute this quantity is constructed each
time the calculation is performed (i.e. each time a snapshot of atoms
is dumped). Thus it can be inefficient to compute/dump this quantity
too frequently or to have multiple compute/dump commands, each of
which computes this quantity.-
[Output info:]
This compute calculates a per-atom vector, which can be accessed by
any command that uses per-atom values from a compute as input. See
"Section_howto 15"_Section_howto.html#howto_15 for an overview of
LAMMPS output options.
[Restrictions:]
This compute is part of the USER-MISC package. It is only enabled if
LAMMPS was built with that package. See the "Making
LAMMPS"_Section_start.html#start_3 section for more info.
The per-atom vector values will be unitless since they are the
integers defined above.
[Related commands:]
"compute centro/atom"_compute_centro_atom.html
[Default:] none
:line
:link(Ackland)
[(Ackland)] Ackland, Jones, Phys Rev B, 73, 054104 (2006).
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