Studying
the effects of small pre-structured seeds on the crystallization
transition in an undercooled monodisperse Lennard-Jones fluid with
transition interface path sampling combined with molecular dynamics
simulations, we analyze the impact of the simultaneous presence of
two seeds with various structures. In the presence of seeds with face-
and body-centered cubic structures, we find that decreasing the seed-to-seed
distance enhances the probability of the crystalline clusters formed
on one of the seeds to grow beyond the critical size, thus, increasing
the crystal nucleation rates. In contrast, when seeds have an icosahedral
structure, the crystalline clusters form mostly in the bulk. The crystal
nucleation rate, however, is also determined by the distance between
the seeds with regular structure in which the lattice spacing is equal
to the bulk lattice constant, pointing to a heterogeneous crystal
nucleation that occurs away from the icosahedrally structured seeds.
For slightly squeezed seeds, the effects of the presence of seeds
with face- and body-centered cubic structures are reduced in comparison
to the regular seeds, and we do not see any effect of the presence
of the second seed for seeds with squeezed icosahedral structure.