pair_style spin/dmi command


pair_style spin/dmi cutoff
  • cutoff = global cutoff pair (distance in metal units)


pair_style spin/dmi 4.0
pair_coeff * * dmi 2.6 0.001 1.0 0.0 0.0
pair_coeff 1 2 dmi 4.0 0.00109 0.0 0.0 1.0


Style spin/dmi computes the Dzyaloshinskii-Moriya (DM) interaction between pairs of magnetic spins:


where si and sj are two neighboring magnetic spins of two particles, eij = (ri - rj)/|ri-rj| is the normalized separation vector between the two particles, and D is the DM vector defining the intensity and the sign of the interaction.

Examples and more explanations about this interaction and its parametrization are reported in (Tranchida).

From this DM interaction, each spin i will be submitted to a magnetic torque omega and its associated atom to a force F (for spin-lattice calculations only).

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


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 Making LAMMPS section for more info.