"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

fix nve/sphere command :h3
fix nve/sphere/omp command :h3

[Syntax:]

fix ID group-ID nve/sphere :pre

ID, group-ID are documented in "fix"_fix.html command :ulb,l
nve/sphere = style name of this fix command :l
zero or more keyword/value pairs may be appended :l
keyword = {update} :l
  {update} value = {dipole}
    dipole = update orientation of dipole moment during integration :pre
:ule

[Examples:]

fix 1 all nve/sphere
fix 1 all nve/sphere update dipole :pre

[Description:]

Perform constant NVE integration to update position, velocity, and
angular velocity for finite-size spherical particles in the group each
timestep.  V is volume; E is energy.  This creates a system trajectory
consistent with the microcanonical ensemble.

This fix differs from the "fix nve"_fix_nve.html command, which
assumes point particles and only updates their position and velocity.

If the {update} keyword is used with the {dipole} value, then the
orientation of the dipole moment of each particle is also updated
during the time integration.  This option should be used for models
where a dipole moment is assigned to particles via use of the
"atom_style dipole"_atom_style.html command.

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Styles with a {cuda}, {gpu}, {omp}, or {opt} suffix are functionally
the same as the corresponding style without the suffix.  They have
been optimized to run faster, depending on your available hardware, as
discussed in "Section_accelerate"_Section_accelerate.html of the
manual.  The accelerated styles take the same arguments and should
produce the same results, except for round-off and precision issues.

These accelerated styles are part of the USER-CUDA, GPU, USER-OMP and OPT
packages, respectively.  They are only enabled if LAMMPS was built with
those packages.  See the "Making LAMMPS"_Section_start.html#start_3
section for more info.

You can specify the accelerated styles explicitly in your input script
by including their suffix, or you can use the "-suffix command-line
switch"_Section_start.html#start_7 when you invoke LAMMPS, or you can
use the "suffix"_suffix.html command in your input script.

See "Section_accelerate"_Section_accelerate.html of the manual for
more instructions on how to use the accelerated styles effectively.

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[Restart, fix_modify, output, run start/stop, minimize info:]

No information about this fix is written to "binary restart
files"_restart.html.  None of the "fix_modify"_fix_modify.html options
are relevant to this fix.  No global or per-atom quantities are stored
by this fix for access by various "output
commands"_Section_howto.html#howto_15.  No parameter of this fix can
be used with the {start/stop} keywords of the "run"_run.html command.
This fix is not invoked during "energy minimization"_minimize.html.

[Restrictions:] 

This fix requires that atoms store torque and angular velocity (omega)
and a radius as defined by the "atom_style sphere"_atom_style.html
command.  If the {dipole} keyword is used, then they must also store a
dipole moment as defined by the "atom_style dipole"_atom_style.html
command.

All particles in the group must be finite-size spheres.  They cannot
be point particles.

[Related commands:]

"fix nve"_fix_nve.html, "fix nve/asphere"_fix_nve_asphere.html

[Default:] none
