AmoebaOutOfPlaneBendForce

class OpenMM::AmoebaOutOfPlaneBendForce

This class implements the Amoeba out-of-plane bend interaction.

To use it, create an OutOfPlaneBendForce object then call addOutOfPlaneBend() once for each outOfPlaneBend. After an out-of-plane bend has been added, you can modify its force field parameters by calling setOutOfPlaneBendParameters(). This will have no effect on Contexts that already exist unless you call updateParametersInContext().

Methods

AmoebaOutOfPlaneBendForce	Create an AmoebaOutOfPlaneBendForce.
getNumOutOfPlaneBends	Get the number of out-of-plane bend terms in the potential function
setAmoebaGlobalOutOfPlaneBendCubic	Set the global cubic term
getAmoebaGlobalOutOfPlaneBendCubic	Get the global cubic term
setAmoebaGlobalOutOfPlaneBendQuartic	Set the global cubic term
getAmoebaGlobalOutOfPlaneBendQuartic	Get the global quartic term
setAmoebaGlobalOutOfPlaneBendPentic	Set the global pentic term
getAmoebaGlobalOutOfPlaneBendPentic	Get the global pentic term
setAmoebaGlobalOutOfPlaneBendSextic	Set the global sextic term
getAmoebaGlobalOutOfPlaneBendSextic	Get the global sextic term
addOutOfPlaneBend	Add an out-of-plane bend term to the force field.
getOutOfPlaneBendParameters	Get the force field parameters for an out-of-plane bend term.
setOutOfPlaneBendParameters	Set the force field parameters for an out-of-plane bend term.
updateParametersInContext	Update the per-bend term parameters in a Context to match those stored in this Force object.
setUsesPeriodicBoundaryConditions	Set whether this force should apply periodic boundary conditions when calculating displacements.
usesPeriodicBoundaryConditions	Returns whether or not this force makes use of periodic boundary conditions.

AmoebaOutOfPlaneBendForce()

Create an AmoebaOutOfPlaneBendForce().

int getNumOutOfPlaneBends() const

Get the number of out-of-plane bend terms in the potential function

void setAmoebaGlobalOutOfPlaneBendCubic(double cubicK)

Set the global cubic term

Parameters

• cubicK – the cubic force constant for the angle

double getAmoebaGlobalOutOfPlaneBendCubic() const

Get the global cubic term

Returns

global cubicK term

void setAmoebaGlobalOutOfPlaneBendQuartic(double quarticK)

Set the global cubic term

Parameters

• quarticK – the quartic force constant for the angle

double getAmoebaGlobalOutOfPlaneBendQuartic() const

Get the global quartic term

Returns

global quartic term

void setAmoebaGlobalOutOfPlaneBendPentic(double penticK)

Set the global pentic term

Parameters

• penticK – the pentic force constant for the angle

double getAmoebaGlobalOutOfPlaneBendPentic() const

Get the global pentic term

Returns

global penticK term

void setAmoebaGlobalOutOfPlaneBendSextic(double sexticK)

Set the global sextic term

Parameters

• sexticK – the sextic force constant for the angle

double getAmoebaGlobalOutOfPlaneBendSextic() const

Get the global sextic term

Returns

global sexticK term

int addOutOfPlaneBend(int particle1, int particle2, int particle3, int particle4, double k)

Add an out-of-plane bend term to the force field.

Parameters

• particle1 – the index of the first particle connected by the outOfPlaneBend

• particle2 – the index of the second particle connected by the outOfPlaneBend

• particle3 – the index of the third particle connected by the outOfPlaneBend

• particle4 – the index of the fourth particle connected by the outOfPlaneBend

• k – the force constant for the out-of-plane bend

Returns

the index of the out-of-plane bend that was added

void getOutOfPlaneBendParameters(int index, int &particle1, int &particle2, int &particle3, int &particle4, double &k) const

Get the force field parameters for an out-of-plane bend term.

Parameters

• index – the index of the outOfPlaneBend for which to get parameters

• particle1 – [out] the index of the first particle connected by the outOfPlaneBend

• particle2 – [out] the index of the second particle connected by the outOfPlaneBend

• particle3 – [out] the index of the third particle connected by the outOfPlaneBend

• particle4 – [out] the index of the fourth particle connected by the outOfPlaneBend

• k – [out] the force constant for the out-of-plane bend

void setOutOfPlaneBendParameters(int index, int particle1, int particle2, int particle3, int particle4, double k)

Set the force field parameters for an out-of-plane bend term.

Parameters

• index – the index of the outOfPlaneBend for which to set parameters

• particle1 – the index of the first particle connected by the outOfPlaneBend

• particle2 – the index of the second particle connected by the outOfPlaneBend

• particle3 – the index of the third particle connected by the outOfPlaneBend

• particle4 – the index of the fourth particle connected by the outOfPlaneBend

• k – the force constant for the out-of-plane bend

void updateParametersInContext(Context &context)

Update the per-bend term 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 setOutOfPlaneBendParameters() to modify this object’s parameters, then call updateParametersInContext() to copy them over to the Context.

The only information this method updates is the values of per-bend term parameters. The set of particles involved in a term cannot be changed, nor can new terms be added.

void setUsesPeriodicBoundaryConditions(bool periodic)

Set whether this force should apply periodic boundary conditions when calculating displacements. Usually this is not appropriate for bonded forces, but there are situations when it can be useful.

bool usesPeriodicBoundaryConditions() const

Returns whether or not this force makes use of periodic boundary conditions.

Returns

true if force uses PBC and false otherwise