Constant¶

class hoomd.md.force.Constant(filter)¶

Bases: Force

Constant force.

Parameters:: filter (hoomd.filter) – Subset of particles on which to apply constant forces.

Constant applies a type dependent constant force and torque on all particles selected by the filter. Constant sets the force and torque to (0,0,0) for particles not selected by the filter.

Examples:

constant = hoomd.md.force.Constant(filter=hoomd.filter.All())
constant.constant_force["A"] = (1, 0, 0)
constant.constant_torque["A"] = (0, 0, 0)

Note

The energy and virial associated with the constant force are 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 Constant:

filter¶

Subset of particles on which to apply constant forces.

Type:: hoomd.filter

constant_force¶

Constant force vector in the global reference frame of the system \([\mathrm{force}]\). It is defined per particle type and defaults to (0.0, 0.0, 0.0) for all types.

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

constant_torque¶

Constant torque vector in the global reference frame of the system \([\mathrm{force} \cdot \mathrm{length}]\). It is defined per particle type and defaults to (0.0, 0.0, 0.0) for all types.

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