  The multispecies Landau collision operator describes the two-particle, small
scattering angle or grazing collisions in a plasma made up of different species
of particles such as electrons and ions. Recently, a structure preserving
deterministic particle method arXiv:1910.03080 has been developed for the
single species spatially homogeneous Landau equation. This method relies on a
regularization of the Landau collision operator so that an approximate
solution, which is a linear combination of Dirac delta distributions, is
well-defined. Based on a weak form of the regularized Landau equation, the time
dependent locations of the Dirac delta functions satisfy a system of ordinary
differential equations. In this work, we extend this particle method to the
multispecies case, and examine its conservation of mass, momentum, and energy,
and decay of entropy properties. We show that the equilibrium distribution of
the regularized multispecies Landau equation is a Maxwellian distribution, and
state a critical condition on the regularization parameters that guarantees a
species independent equilibrium temperature. A convergence study comparing an
exact multispecies BKW solution to the particle solution shows approximately
2nd order accuracy. Important physical properties such as conservation, decay
of entropy, and equilibrium distribution of the particle method are
demonstrated with several numerical examples.
