DisplacementCapped

class hoomd.md.methods.rattle.DisplacementCapped(filter: ParticleFilter | CustomFilter, maximum_displacement: Variant | float, manifold_constraint: Manifold, tolerance: float = 1e-06)

Bases: NVE

Newtonian dynamics with a cap on the maximum displacement per time step.

Integration is via a maximum displacement capped Velocity-Verlet with RATTLE constraint. This class is useful to relax a simulation on a manifold.

Warning

This method does not conserve energy or momentum.

Parameters:

  • filter (hoomd.filter.filter_like) – Subset of particles on which to apply this method.

  • maximum_displacement (hoomd.variant.variant_like) – The maximum displacement allowed for a particular timestep \([\mathrm{length}]\).

  • manifold_constraint (hoomd.md.manifold.Manifold) – Manifold constraint.

  • tolerance (float, optional) – Defines the tolerated error particles are allowed to deviate from the manifold in terms of the implicit function. The units of tolerance match that of the selected manifold’s implicit function. Defaults to 1e-6

DisplacementCapped performs constant volume simulations as described in hoomd.md.methods.DisplacementCapped. In addition the particles are constrained to a manifold by using the RATTLE algorithm.

Example

sphere = hoomd.md.manifold.Sphere(r=5)
relax_rattle = hoomd.md.methods.rattle.DisplacementCapped(
    filter=hoomd.filter.All(),
    maximum_displacement=0.01,
    manifold_constraint=sphere,
)
simulation.operations.integrator.methods = [relax_rattle]

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 MethodRATTLE:

manifold_constraint

Manifold constraint. Read more...

tolerance

Defines the tolerated error particles are allowed to deviate from the manifold in terms of the implicit function. Read more...

Members inherited from NVE:

filter

Subset of particles on which to apply this method. Read more...

Members defined in DisplacementCapped:

maximum_displacement

The maximum displacement allowed for a particular timestep \([\mathrm{length}]\).

Type:

hoomd.variant.variant_like