ActiveOnManifold¶

class hoomd.md.force.ActiveOnManifold(filter, manifold_constraint)¶

Bases: Active

Active force on a manifold.

Parameters:

filter (hoomd.filter) – Subset of particles on which to apply active forces.
manifold_constraint (hoomd.md.manifold.Manifold) – Manifold constraint.

ActiveOnManifold computes a constrained active force and torque on all particles selected by the filter similar to Active. ActiveOnManifold restricts the forces to the local tangent plane of the manifold constraint. For more information see Active.

Hint

Use ActiveOnManifold with a md.methods.rattle integration method with the same manifold constraint.

Note

To introduce rotational diffusion to the particle orientations, use create_diffusion_updater. The rotational diffusion occurs in the local tangent plane of the manifold.

Examples:

all = filter.All()
sphere = hoomd.md.manifold.Sphere(r=10)
active = hoomd.md.force.ActiveOnManifold(
    filter=hoomd.filter.All(),
    rotation_diff=0.01,
    manifold_constraint=sphere,
)
active.active_force["A", "B"] = (1, 0, 0)
active.active_torque["A", "B"] = (0, 0, 0)

Members inherited from AutotunedObject:

property kernel_parameters¶: Kernel parameters. Read more...

property is_tuning_complete¶: Check if kernel parameter tuning is complete. Read more...

tune_kernel_parameters()¶: Start tuning kernel parameters. Read more...

Members inherited from Force:

additional_energy¶: Additional energy term. Read more...

additional_virial¶: Additional virial tensor term \(W_\mathrm{additional}\). Read more...

cpu_local_force_arrays¶: Local force arrays on the CPU. Read more...

energies¶: Energy contribution \(U_i\) from each particle. Read more...

energy¶: The potential energy \(U\) of the system from this force. Read more...

forces¶: The force \(\vec{F}_i\) applied to each particle. Read more...

gpu_local_force_arrays¶: Local force arrays on the GPU. Read more...

torques¶: The torque \(\vec{\tau}_i\) applied to each particle. Read more...

virials¶: Virial tensor contribution \(W_i\) from each particle. Read more...

Members defined in ActiveOnManifold:

filter¶

Subset of particles on which to apply active forces.

Type:: hoomd.filter

manifold_constraint¶

Manifold constraint.

Type:: hoomd.md.manifold.Manifold

active_force¶

Active force vector in the local reference frame of the particle \([\mathrm{force}]\). It is defined per particle type and stays constant during the simulation.

Type: TypeParameter [particle_type, tuple [float, float, float]]

active_torque¶

Active torque vector in local reference frame of the particle \([\mathrm{force} \cdot \mathrm{length}]\). It is defined per particle type and stays constant during the simulation.

Type: TypeParameter [particle_type, tuple [float, float, float]]