"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)

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fix nve/spin command :h3

[Syntax:]

fix ID group-ID nve/spin keyword values :pre

ID, group-ID are documented in "fix"_fix.html command :ulb,l
nve/spin = style name of this fix command :l
keyword = {lattice} :l
  {lattice} value = {no} or {yes} :pre
:ule

[Examples:]

fix 3 all nve/spin lattice yes
fix 1 all nve/spin lattice no :pre

[Description:]

Perform a symplectic integration for the spin or spin-lattice system.

The {lattice} keyword defines if the spins are integrated on a lattice
of fixed atoms (lattice = no), or if atoms are moving (lattice = yes).

By default (lattice = yes), a spin-lattice integration is performed.

The {nve/spin} fix applies a Suzuki-Trotter decomposition to
the equations of motion of the spin lattice system, following the scheme:

:c,image(Eqs/fix_integration_spin_stdecomposition.jpg)

according to the implementation reported in "(Omelyan)"_#Omelyan1.

A sectoring method enables this scheme for parallel calculations.
The implementation of this sectoring algorithm is reported
in "(Tranchida)"_#Tranchida1.

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[Restrictions:]

This fix style can only be used if LAMMPS was built with the SPIN
package.  See the "Build package"_Build_package.html doc page for more
info.

To use the spin algorithm, it is necessary to define a map with
the atom_modify command. Typically, by adding the command:

atom_modify map array :pre

before you create the simulation box. Note that the keyword "hash"
instead of "array" is also valid.

[Related commands:]

"atom_style spin"_atom_style.html, "fix nve"_fix_nve.html

[Default:] none

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:link(Omelyan1)
[(Omelyan)] Omelyan, Mryglod, and Folk. Phys. Rev. Lett.
86(5), 898. (2001).

:link(Tranchida1)
[(Tranchida)] Tranchida, Plimpton, Thibaudeau and Thompson,
Journal of Computational Physics, 372, 406-425, (2018).
