# 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. 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

• 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

• 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

• 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

• 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.

• 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.

• 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.

• 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.

bool usesPeriodicBoundaryConditions() const

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

Returns: true if nonbondedMethod uses PBC and false otherwise