This class implements an interaction between triplets of particles that varies with the angle between them. More...

#include <AmoebaAngleForce.h>

Inheritance diagram for AmoebaAngleForce:

Public Member Functions
	AmoebaAngleForce ()
	Create an AmoebaAngleForce. More...

int	getNumAngles () const
	Get the number of angle stretch terms in the potential function. More...

void	setAmoebaGlobalAngleCubic (double cubicK)
	Set the global cubic term. More...

double	getAmoebaGlobalAngleCubic (void) const
	Get the global cubic term. More...

void	setAmoebaGlobalAngleQuartic (double quarticK)
	Set the global quartic term. More...

double	getAmoebaGlobalAngleQuartic (void) const
	Get the global quartic term. More...

void	setAmoebaGlobalAnglePentic (double penticK)
	Set the global pentic term. More...

double	getAmoebaGlobalAnglePentic (void) const
	Get the global pentic term. More...

void	setAmoebaGlobalAngleSextic (double sexticK)
	Set the global sextic term. More...

double	getAmoebaGlobalAngleSextic (void) const
	Get the global sextic term. More...

int	addAngle (int particle1, int particle2, int particle3, double length, double quadraticK)
	Add an angle term to the force field. More...

void	getAngleParameters (int index, int &particle1, int &particle2, int &particle3, double &length, double &quadraticK) const
	Get the force field parameters for an angle term. More...

void	setAngleParameters (int index, int particle1, int particle2, int particle3, double length, double quadraticK)
	Set the force field parameters for an angle term. More...

void	updateParametersInContext (Context &context)
	Update the per-angle parameters in a Context to match those stored in this Force object. More...

Public Member Functions inherited from Force
	Force ()

virtual	~Force ()

int	getForceGroup () const
	Get the force group this Force belongs to. More...

void	setForceGroup (int group)
	Set the force group this Force belongs to. More...

Protected Member Functions
ForceImpl *	createImpl () const
	When a Context is created, it invokes this method on each Force in the System. More...

Protected Member Functions inherited from Force
ForceImpl &	getImplInContext (Context &context)
	Get the ForceImpl corresponding to this Force in a Context. More...

ContextImpl &	getContextImpl (Context &context)
	Get the ContextImpl corresponding to a Context. More...

Protected Attributes
double	_globalCubicK

double	_globalQuarticK

double	_globalPenticK

double	_globalSexticK

Detailed Description

This class implements an interaction between triplets of particles that varies with the angle between them.

The interaction is defined by a 6th order polynomial. Only the quadratic term is set per-angle. The coefficients of the higher order terms each have a single value that is set globally.

To use it, create an AmoebaAngleForce object then call addAngle() once for each angle. After an angle has been added, you can modify its force field parameters by calling setAngleParameters(). This will have no effect on Contexts that already exist unless you call updateParametersInContext().

Constructor & Destructor Documentation

AmoebaAngleForce ( )

Create an AmoebaAngleForce.

Member Function Documentation

int addAngle	(	int	particle1,
		int	particle2,
		int	particle3,
		double	length,
		double	quadraticK
	)

Add an angle term to the force field.

Parameters

particle1	the index of the first particle connected by the angle
particle2	the index of the second particle connected by the angle
particle3	the index of the third particle connected by the angle
length	the angle measured in degrees
quadratic	k the quadratic force constant for the angle, measured in kJ/mol/radian^2

Returns: the index of the angle that was added

ForceImpl* createImpl ( ) const

protectedvirtual

When a Context is created, it invokes this method on each Force in the System.

It should create a new ForceImpl object which can be used by the context for calculating forces. The ForceImpl will be deleted automatically when the Context is deleted.

Implements Force.

double getAmoebaGlobalAngleCubic ( void ) const

Get the global cubic term.

Returns: global cubicK term

double getAmoebaGlobalAnglePentic ( void ) const

Get the global pentic term.

Returns: global penticK term

double getAmoebaGlobalAngleQuartic ( void ) const

Get the global quartic term.

Returns: global quartic term

double getAmoebaGlobalAngleSextic ( void ) const

Get the global sextic term.

Returns: global sextic term

void getAngleParameters	(	int	index,
		int &	particle1,
		int &	particle2,
		int &	particle3,
		double &	length,
		double &	quadraticK
	)		const

Get the force field parameters for an angle term.

Parameters

index	the index of the angle for which to get parameters
particle1	the index of the first particle connected by the angle
particle2	the index of the second particle connected by the angle
particle3	the index of the third particle connected by the angle
length	the equilibrium angle, measured in degress
quadratic	k the quadratic force constant for the angle, measured in kJ/mol/radian^2

int getNumAngles ( ) const

inline

Get the number of angle stretch terms in the potential function.

void setAmoebaGlobalAngleCubic ( double cubicK )

Set the global cubic term.

Parameters

cubicK the cubic force constant for the angle

void setAmoebaGlobalAnglePentic ( double penticK )

Set the global pentic term.

Parameters

penticK the pentic force constant for the angle

void setAmoebaGlobalAngleQuartic ( double quarticK )

Set the global quartic term.

Parameters

quarticK the quartic force constant for the angle

void setAmoebaGlobalAngleSextic ( double sexticK )

Set the global sextic term.

Parameters

sexticK the sextic force constant for the angle

void setAngleParameters	(	int	index,
		int	particle1,
		int	particle2,
		int	particle3,
		double	length,
		double	quadraticK
	)

Set the force field parameters for an angle term.

Parameters

index	the index of the angle for which to set parameters
particle1	the index of the first particle connected by the angle
particle2	the index of the second particle connected by the angle
particle3	the index of the third particle connected by the angle
length	the equilibrium angle, measured in degrees
quadratic	k the quadratic force constant for the angle, measured in kJ/mol/radian^2

void updateParametersInContext ( Context & context )

Update the per-angle parameters in a Context to match those stored in this Force object.

This method provides an efficient method to update certain parameters in an existing Context without needing to reinitialize it. Simply call setAngleParameters() to modify this object's parameters, then call updateParametersInState() to copy them over to the Context.

The only information this method updates is the values of per-angle parameters. The set of particles involved in an angle cannot be changed, nor can new angles be added.

Member Data Documentation

double _globalCubicK

protected

double _globalPenticK

protected

double _globalQuarticK

protected

double _globalSexticK

protected

The documentation for this class was generated from the following file:

AmoebaAngleForce.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation