Carbon¶
C cells (40 × 40 × 40 Å) walking the sp² ↔ sp³ axis rather than the disorder axis the other materials walk. Each Voronoi grain is sampled from either graphite (sp², 3-coordinated, 120°) or diamond (sp³, 4-coordinated, 109.5°) and the regime sets the mix:
Regime |
w_graphite |
w_diamond |
character |
|---|---|---|---|
|
1.00 |
0.00 |
nanocrystalline graphite (all sp²) |
|
0.50 |
0.50 |
sp²/sp³ mixed nanocrystalline |
|
0.00 |
1.00 |
nanocrystalline diamond (all sp³) |
Every regime is nanocrystalline (grain_size = 18 Å); the variable
is the grain chemistry, not the grain size. Shell-relax weights are
fixed at bond_weight=2.5, angle_weight=1.2, repulsion_weight=2.0.
The
composite shell target carries two virtual species (sp2_C,
sp3_C); each grain’s atoms inherit the species index of the master
they came from, so 3-coordinated graphite atoms develop bonds at
120° and 4-coordinated diamond atoms develop bonds at 109.5°
inside the same cell.
Static vs refined¶
Top row is Supercell.generate() with the static-relaxation
pipeline only (FIRE quench, no orientation search); bottom row is
the same cell with refine_orientations=True enabled. The SO(3)
coordinate search that aligns each grain’s lattice to its local
environment before the same final FIRE quench runs. Drag any panel
to orbit; all six rotate in sync.
g(r) overlay: static vs refined, all 6 cases¶
Six g(r) curves on a single radial axis: each regime’s static and refined post-FIRE state, overlaid for direct comparison. The pair dropdown below the plot lets you switch between the sp²-C and sp³-C channels.
Per-regime trajectories¶
Click any regime for the orientation-refinement movie, the FIRE quench movie (with sp³ tetrahedra rendered at the final state), the cost trace, and the g3 distribution.