OpenMM

This class implements an interaction between groups of four particles that varies with the torsion angle between them according to the RyckaertBellemans potential. More...
Public Member Functions  
def  getNumTorsions 
getNumTorsions(self) > int  
def  addTorsion 
addTorsion(self, particle1, particle2, particle3, particle4, c0, c1, c2, c3, c4, c5) > int  
def  getTorsionParameters 
Get the force field parameters for a RyckaertBellemans torsion term.  
def  setTorsionParameters 
Set the force field parameters for a RyckaertBellemans torsion term.  
def  updateParametersInContext 
Update the pertorsion parameters in a Context to match those stored in this Force object.  
def  usesPeriodicBoundaryConditions 
usesPeriodicBoundaryConditions(self) > bool  
def  __init__ 
__init__(self) > RBTorsionForce __init__(self, other) > RBTorsionForce  
Public Attributes  
this 
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().
def __init__  (  self,  
args  
) 
__init__(self) > RBTorsionForce __init__(self, other) > RBTorsionForce
Create a RBTorsionForce.
def addTorsion  (  self,  
particle1,  
particle2,  
particle3,  
particle4,  
c0,  
c1,  
c2,  
c3,  
c4,  
c5  
) 
addTorsion(self, particle1, particle2, particle3, particle4, c0, c1, c2, c3, c4, c5) > int
Add a RyckaertBellemans torsion term to the force field.
particle1  (int) the index of the first particle forming the torsion 
particle2  (int) the index of the second particle forming the torsion 
particle3  (int) the index of the third particle forming the torsion 
particle4  (int) the index of the fourth particle forming the torsion 
c0  (double) the coefficient of the constant term, measured in kJ/mol 
c1  (double) the coefficient of the 1st order term, measured in kJ/mol 
c2  (double) the coefficient of the 2nd order term, measured in kJ/mol 
c3  (double) the coefficient of the 3rd order term, measured in kJ/mol 
c4  (double) the coefficient of the 4th order term, measured in kJ/mol 
c5  (double) the coefficient of the 5th order term, measured in kJ/mol 
def getNumTorsions  (  self  ) 
getNumTorsions(self) > int
Get the number of RyckaertBellemans torsion terms in the potential function
def getTorsionParameters  (  self,  
index  
) 
Get the force field parameters for a RyckaertBellemans torsion term.
index  (int) the index of the torsion for which to get parameters 
def setTorsionParameters  (  self,  
index,  
particle1,  
particle2,  
particle3,  
particle4,  
c0,  
c1,  
c2,  
c3,  
c4,  
c5  
) 
Set the force field parameters for a RyckaertBellemans torsion term.
index  (int) the index of the torsion for which to set parameters 
particle1  (int) the index of the first particle forming the torsion 
particle2  (int) the index of the second particle forming the torsion 
particle3  (int) the index of the third particle forming the torsion 
particle4  (int) the index of the fourth particle forming the torsion 
c0  (double) the coefficient of the constant term, measured in kJ/mol 
c1  (double) the coefficient of the 1st order term, measured in kJ/mol 
c2  (double) the coefficient of the 2nd order term, measured in kJ/mol 
c3  (double) the coefficient of the 3rd order term, measured in kJ/mol 
c4  (double) the coefficient of the 4th order term, measured in kJ/mol 
c5  (double) the coefficient of the 5th order term, measured in kJ/mol 
def updateParametersInContext  (  self,  
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 updateParametersInContext() 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.
def usesPeriodicBoundaryConditions  (  self  ) 
usesPeriodicBoundaryConditions(self) > bool
Returns whether or not this force makes use of periodic boundary conditions.
Reimplemented from Force.