Force¶
-
class
OpenMM
::
Force
¶ Force
objects apply forces to the particles in aSystem
, or alter their behavior in other ways. This is an abstract class. Subclasses define particular forces.More specifically, a
Force
object can do any or all of the following:Add a contribution to the force on each particle
Add a contribution to the potential energy of the
System
Modify the positions and velocities of particles at the start of each time step
Define parameters which are stored in the
Context
and can be modified by the userChange the values of parameters defined by other
Force
objects at the start of each time step
Forces may be organized into “force groups”. This is used for multiple time step integration, and allows subsets of the Forces in a
System
to be evaluated at different times. By default, all Forces are in group 0. CallsetForceGroup()
to change this. SomeForce
subclasses may provide additional methods to further split their computations into multiple groups. Be aware that particular Platforms may place restrictions on the use of force groups, such as requiring all nonbonded forces to be in the same group.Methods
Get the force group this
Force
belongs to.Set the force group this
Force
belongs to.Returns whether or not this force makes use of periodic boundary conditions.
-
Force
()¶
-
~Force
()¶
-
void
setForceGroup
(int group)¶ Set the force group this
Force
belongs to.- Parameters
group – the group index. Legal values are between 0 and 31 (inclusive).
-
bool
usesPeriodicBoundaryConditions
() const¶ Returns whether or not this force makes use of periodic boundary conditions. This method should be overridden for all
Force
subclasses, or aOpenMM::OpenMMException
will be thrown- Returns
true if
Force
uses periodic boundaries or false if it does not