"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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pair_style spin/magelec command :h3

[Syntax:]

pair_style spin/magelec cutoff :pre

cutoff = global cutoff pair (distance in metal units) :ulb,l

:ule

[Examples:]

pair_style spin/magelec 4.5
pair_coeff * * magelec 4.5 0.00109 1.0 1.0 1.0 :pre

[Description:]

Style {spin/me} computes a magneto-electric interaction between
pairs of magnetic spins. According to the derivation reported in
"(Katsura)"_#Katsura1, this interaction is defined as:

:c,image(Eqs/pair_spin_me_interaction.jpg)

where si and sj are neighboring magnetic spins of two particles,
eij = (ri - rj)/|ri-rj| is the normalized separation vector between the
two particles, and E is an electric polarization vector.
The norm and direction of E are giving the intensity and the
direction of a screened dielectric atomic polarization (in eV).

From this magneto-electric interaction, each spin i will be submitted
to a magnetic torque omega, and its associated atom can be submitted to a
force F for spin-lattice calculations (see "fix_nve_spin"_fix_nve_spin.html),
such as:

:c,image(Eqs/pair_spin_me_forces.jpg)

with h the Planck constant (in metal units).

More details about the derivation of these torques/forces are reported in
"(Tranchida)"_#Tranchida4.

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[Restrictions:]

All the {pair/spin} styles are part of the SPIN package.  These styles
are only enabled if LAMMPS was built with this package, and if the
atom_style "spin" was declared.  See the "Build
package"_Build_package.html doc page for more info.

[Related commands:]

"atom_style spin"_atom_style.html, "pair_coeff"_pair_coeff.html,
"pair_spin_exchange"_pair_spin_exchange.html, "pair_eam"_pair_eam.html,

[Default:] none

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:link(Katsura1)
[(Katsura)] H. Katsura, N. Nagaosa, A.V. Balatsky. Phys. Rev. Lett., 95(5), 057205. (2005)

:link(Tranchida4)
[(Tranchida)] Tranchida, Plimpton, Thibaudeau, and Thompson,
Journal of Computational Physics, 372, 406-425, (2018).
