This class implements an interaction between groups of four particles that varies with the torsion angle between them according to the RyckaertBellemans potential.
More...
#include <RBTorsionForce.h>

 RBTorsionForce () 
 Create a RBTorsionForce. More...


int  getNumTorsions () const 
 Get the number of RyckaertBellemans torsion terms in the potential function. More...


int  addTorsion (int particle1, int particle2, int particle3, int particle4, double c0, double c1, double c2, double c3, double c4, double c5) 
 Add a RyckaertBellemans torsion term to the force field. More...


void  getTorsionParameters (int index, int &particle1, int &particle2, int &particle3, int &particle4, double &c0, double &c1, double &c2, double &c3, double &c4, double &c5) const 
 Get the force field parameters for a RyckaertBellemans torsion term. More...


void  setTorsionParameters (int index, int particle1, int particle2, int particle3, int particle4, double c0, double c1, double c2, double c3, double c4, double c5) 
 Set the force field parameters for a RyckaertBellemans torsion term. More...


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


 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...


This class implements an interaction between groups of four particles that varies with the torsion angle between them according to the RyckaertBellemans potential.
To use it, create an RBTorsionForce object then call addTorsion() once for each torsion. After a torsion has been added, you can modify its force field parameters by calling setTorsionParameters(). This will have no effect on Contexts that already exist unless you call updateParametersInContext().
int addTorsion 
( 
int 
particle1, 


int 
particle2, 


int 
particle3, 


int 
particle4, 


double 
c0, 


double 
c1, 


double 
c2, 


double 
c3, 


double 
c4, 


double 
c5 

) 
 
Add a RyckaertBellemans torsion term to the force field.
 Parameters

particle1  the index of the first particle forming the torsion 
particle2  the index of the second particle forming the torsion 
particle3  the index of the third particle forming the torsion 
particle4  the index of the fourth particle forming the torsion 
c0  the coefficient of the constant term, measured in kJ/mol 
c1  the coefficient of the 1st order term, measured in kJ/mol 
c2  the coefficient of the 2nd order term, measured in kJ/mol 
c3  the coefficient of the 3rd order term, measured in kJ/mol 
c4  the coefficient of the 4th order term, measured in kJ/mol 
c5  the coefficient of the 5th order term, measured in kJ/mol 
 Returns
 the index of the torsion that was added
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.
int getNumTorsions 
( 
 ) 
const 

inline 
Get the number of RyckaertBellemans torsion terms in the potential function.
void getTorsionParameters 
( 
int 
index, 


int & 
particle1, 


int & 
particle2, 


int & 
particle3, 


int & 
particle4, 


double & 
c0, 


double & 
c1, 


double & 
c2, 


double & 
c3, 


double & 
c4, 


double & 
c5 

) 
 const 
Get the force field parameters for a RyckaertBellemans torsion term.
 Parameters

index  the index of the torsion for which to get parameters 
particle1  the index of the first particle forming the torsion 
particle2  the index of the second particle forming the torsion 
particle3  the index of the third particle forming the torsion 
particle4  the index of the fourth particle forming the torsion 
c0  the coefficient of the constant term, measured in kJ/mol 
c1  the coefficient of the 1st order term, measured in kJ/mol 
c2  the coefficient of the 2nd order term, measured in kJ/mol 
c3  the coefficient of the 3rd order term, measured in kJ/mol 
c4  the coefficient of the 4th order term, measured in kJ/mol 
c5  the coefficient of the 5th order term, measured in kJ/mol 
void setTorsionParameters 
( 
int 
index, 


int 
particle1, 


int 
particle2, 


int 
particle3, 


int 
particle4, 


double 
c0, 


double 
c1, 


double 
c2, 


double 
c3, 


double 
c4, 


double 
c5 

) 
 
Set the force field parameters for a RyckaertBellemans torsion term.
 Parameters

index  the index of the torsion for which to set parameters 
particle1  the index of the first particle forming the torsion 
particle2  the index of the second particle forming the torsion 
particle3  the index of the third particle forming the torsion 
particle4  the index of the fourth particle forming the torsion 
c0  the coefficient of the constant term, measured in kJ/mol 
c1  the coefficient of the 1st order term, measured in kJ/mol 
c2  the coefficient of the 2nd order term, measured in kJ/mol 
c3  the coefficient of the 3rd order term, measured in kJ/mol 
c4  the coefficient of the 4th order term, measured in kJ/mol 
c5  the coefficient of the 5th order term, measured in kJ/mol 
void updateParametersInContext 
( 
Context & 
context  ) 

Update the pertorsion 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 setTorsionParameters() 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 pertorsion parameters. The set of particles involved in a torsion cannot be changed, nor can new torsions be added.
The documentation for this class was generated from the following file: