forked from lijiext/lammps
93 lines
3.2 KiB
Plaintext
93 lines
3.2 KiB
Plaintext
"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 property/atom command :h3
|
|
|
|
[Syntax:]
|
|
|
|
compute ID group-ID property/atom input1 input2 ... :pre
|
|
|
|
ID, group-ID are documented in "compute"_compute.html command :ulb,l
|
|
property/atom = style name of this compute command :l
|
|
input = one or more atom attributes :l
|
|
possible attributes = id, mol, type, mass,
|
|
x, y, z, xs, ys, zs, xu, yu, zu, ix, iy, iz,
|
|
vx, vy, vz, fx, fy, fz,
|
|
q, mux, muy, muz,
|
|
radius, omegax, omegay, omegaz,
|
|
angmomx, angmomy, angmomz,
|
|
quatw, quati, quatj, quatk, tqx, tqy, tqz :pre
|
|
|
|
id = atom ID
|
|
mol = molecule ID
|
|
type = atom type
|
|
mass = atom mass
|
|
x,y,z = unscaled atom coordinates
|
|
xs,ys,zs = scaled atom coordinates
|
|
xu,yu,zu = unwrapped atom coordinates
|
|
ix,iy,iz = box image that the atom is in
|
|
vx,vy,vz = atom velocities
|
|
fx,fy,fz = forces on atoms
|
|
q = atom charge
|
|
mux,muy,muz = orientation of dipolar atom
|
|
radius = radius of extended spherical particle
|
|
omegax,omegay,omegaz = angular velocity of extended particle
|
|
angmomx,angmomy,angmomz = angular momentum of extended particle
|
|
quatw,quati,quatj,quatk = quaternion components for aspherical particles
|
|
tqx,tqy,tqz = torque on extended particles :pre
|
|
:ule
|
|
|
|
[Examples:]
|
|
|
|
compute 1 all property/atom xs vx fx mux
|
|
compute 2 all property/atom type
|
|
compute 1 all property/atom ix iy iz :pre
|
|
|
|
[Description:]
|
|
|
|
Define a computation that simply stores atom attributes for each atom
|
|
in the group. This is useful so that the values can be used by other
|
|
"output commands"_Section_howto.html#4_15 that take computes as
|
|
inputs. See for example, the "compute reduce"_compute_reduce.html,
|
|
"fix ave/atom"_fix_ave_atom.html, "fix ave/histo"_fix_ave_histo.html,
|
|
"fix ave/spatial"_fix_ave_spatial.html, and "atom-style
|
|
variable"_variable.html commands.
|
|
|
|
The list of possible attributes is the same as that used by the "dump
|
|
custom"_dump.html command, which describes their meaning. Basically,
|
|
this list gives your input script access to any per-atom quantity
|
|
stored by LAMMPS.
|
|
|
|
The values are stored in a per-atom vector or array as
|
|
discussed below. Zeroes are stored for atoms not in the specified
|
|
group.
|
|
|
|
[Output info:]
|
|
|
|
This compute calculates a per-atom vector or per-atom array depending
|
|
on the number of input values. If a single input is specified, a
|
|
per-atom vector is produced. If two or more inputs are specified, a
|
|
per-atom array is produced where the number of columns = the number of
|
|
inputs. The vector or array can be accessed by any command that uses
|
|
per-atom values from a compute as input. See "this
|
|
section"_Section_howto.html#4_15 for an overview of LAMMPS output
|
|
options.
|
|
|
|
The vector or array values will be in whatever "units"_units.html the
|
|
corresponding attribute is in, e.g. velocity units for vx, charge
|
|
units for q, etc.
|
|
|
|
[Restrictions:] none
|
|
|
|
[Related commands:]
|
|
|
|
"dump custom"_dump.html, "compute reduce"_compute_reduce.html, "fix
|
|
ave/atom"_fix_ave_atom.html, "fix ave/spatial"_fix_ave_spatial.html
|
|
|
|
[Default:] none
|