CosineSquared¶

class hoomd.md.angle.CosineSquared¶

Bases: Angle

Cosine squared angle force.

CosineSquared computes forces, virials, and energies on all angles in the simulation state with:

\[U(\theta) = \frac{1}{2} k \left( \cos\theta - \cos\theta_0 \right)^2\]

CosineSquared is used in the gromos96 and MARTINI force fields.

Examples:

cosinesq = angle.CosineSquared()
cosinesq.params["A-A-A"] = dict(k=3.0, t0=0.7851)
cosinesq.params["A-B-A"] = dict(k=100.0, t0=1.0)

Members inherited from AutotunedObject:

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

Members inherited from Force:

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

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

params¶

The parameter of the harmonic bonds for each particle type. The dictionary has the following keys: