Long-range order

Silicon with larger ~18 Å grains. The pair correlation function retains sharper peaks out to longer distances than the MRO case, approaching the nanocrystalline regime.

Parameters

from ase.build import bulk
import tricor as tc

atoms = bulk("Si", "diamond", a=5.431)
shell_target = tc.CoordinationShellTarget.from_atoms(atoms, phi_num_bins=90)

cell = tc.Supercell.from_atoms(
    atoms,
    cell_dim_angstroms=(40, 40, 40),
    r_max=10, r_step=0.1, phi_num_bins=90,
    rng_seed=42,
)
cell.generate(
    shell_target,
    num_steps=200,
    grain_size=15.0,
    bond_weight=2.4,
    angle_weight=1.0,
    repulsion_weight=2.3,
    hard_core_scale=0.93,
    nonbond_push_scale=0.85,
    displacement_sigma=0.035,
)

Relaxation trajectory

Interactive 3D viewer of the shell-relaxation trajectory (40 × 40 × 40 Å cell). Drag to rotate, scroll to zoom. Controls below the canvas play, scrub, and change playback speed.

g3 distribution

Measured from the final (post-relaxation) atoms. The heatmap is the reduced three-body density in units of the uniform random reference, where white = 1.0, blue = depleted, red = enhanced. The lower panel shows the pair profile g(r); the shaded amber band marks the first-neighbour shell used as the root-bond integration window for the g3 slice. For silicon there is a single Si-Si-Si triplet channel.