jaxdem.forces.wca

Classes

WCA([laws])

Weeks-Chandler-Andersen (WCA) purely repulsive Lennard-Jones interaction.

class jaxdem.forces.wca.WCA(laws: Tuple[ForceModel, ...] = ())

Bases: ForceModel

Weeks-Chandler-Andersen (WCA) purely repulsive Lennard-Jones interaction.

Uses material-pair parameter:

• epsilon_eff[mi, mj]

The length scale \(\sigma_{ij}\) is derived from particle radii (like spring.py):

\[\sigma_{ij} = R_i + R_j\]

Potential (for r < r_c = 2^(1/6) sigma):

U(r) = 4 eps [(sigma/r)^12 - (sigma/r)^6] + eps

else:

U(r) = 0

Force:

F_vec = 24 eps (2 (sigma/r)^12 - (sigma/r)^6) * (1/r^2) * r_ij

static force(i: int, j: int, pos: jax.Array, state: State, system: System) → Tuple[jax.Array, jax.Array]

static energy(i: int, j: int, pos: jax.Array, state: State, system: System) → jax.Array

property required_material_properties: Tuple[str, ...]

A static tuple of strings specifying the material properties required by this force model.

These properties (e.g., ‘young_eff’, ‘restitution’, …) must be present in the System.mat_table for the model to function correctly. This is used for validation.