AmoebaInPlaneAngleForce¶
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class
simtk.openmm.openmm.
AmoebaInPlaneAngleForce
(*args)¶ This class implements an interaction at trigonal centers corresponding to the projected in-plane angle bend energy between four particles. The interaction is defined by a 6th order polynomial in the angle between them. 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 AmoebaInPlaneAngleForce 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().
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__init__
(self) → AmoebaInPlaneAngleForce¶ __init__(self, other) -> AmoebaInPlaneAngleForce Create an AmoebaAngleForce.
Methods
__init__
(self)__init__(self, other) -> AmoebaInPlaneAngleForce Create an AmoebaAngleForce.
addAngle
(self, particle1, particle2, …)Add an angle term to the force field.
Get the global cubic term
Get the global pentic term
Get the global quartic term
Get the global sextic term
getAngleParameters
(self, index)Get the force field parameters for an angle term.
getForceGroup
(self)Get the force group this Force belongs to.
getNumAngles
(self)Get the number of in-plane angle terms in the potential function
setAmoebaGlobalInPlaneAngleCubic
(self, cubicK)Set the global cubic term
setAmoebaGlobalInPlaneAnglePentic
(self, penticK)Set the global pentic term
setAmoebaGlobalInPlaneAngleQuartic
(self, …)Set the global quartic term
setAmoebaGlobalInPlaneAngleSextic
(self, sexticK)Set the global sextic term
setAngleParameters
(self, index, particle1, …)Set the force field parameters for an angle term.
setForceGroup
(self, group)Set the force group this Force belongs to.
setUsesPeriodicBoundaryConditions
(self, periodic)Set whether this force should apply periodic boundary conditions when calculating displacements.
updateParametersInContext
(self, context)Update the per-angle parameters in a Context to match those stored in this Force object.
Returns whether or not this force makes use of periodic boundary conditions.
Attributes
The membership flag
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property
thisown
¶ The membership flag
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getNumAngles
(self) → int¶ Get the number of in-plane angle terms in the potential function
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setAmoebaGlobalInPlaneAngleCubic
(self, cubicK)¶ Set the global cubic term
- Parameters
cubicK (double) – the cubic force constant for the angle
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getAmoebaGlobalInPlaneAngleCubic
(self) → double¶ Get the global cubic term
- Returns
global cubicK term
- Return type
double
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setAmoebaGlobalInPlaneAngleQuartic
(self, quarticK)¶ Set the global quartic term
- Parameters
quarticK (double) – the quartic force constant for the angle
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getAmoebaGlobalInPlaneAngleQuartic
(self) → double¶ Get the global quartic term
- Returns
global quartic term
- Return type
double
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setAmoebaGlobalInPlaneAnglePentic
(self, penticK)¶ Set the global pentic term
- Parameters
penticK (double) – the pentic force constant for the angle
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getAmoebaGlobalInPlaneAnglePentic
(self) → double¶ Get the global pentic term
- Returns
global penticK term
- Return type
double
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setAmoebaGlobalInPlaneAngleSextic
(self, sexticK)¶ Set the global sextic term
- Parameters
sexticK (double) – the sextic force constant for the angle
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getAmoebaGlobalInPlaneAngleSextic
(self) → double¶ Get the global sextic term
- Returns
global sextic term
- Return type
double
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addAngle
(self, particle1, particle2, particle3, particle4, length, quadraticK) → int¶ Add an angle term to the force field.
- Parameters
particle1 (int) – the index of the first particle connected by the angle
particle2 (int) – the index of the second particle connected by the angle
particle3 (int) – the index of the third particle connected by the angle
particle4 (int) – the index of the fourth particle connected by the angle
length (double) – the equilibrium angle, measured in radians
quadraticK (double) – the quadratic force constant for the angle measured in kJ/mol/radian^2
- Returns
the index of the angle that was added
- Return type
int
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getAngleParameters
(self, index)¶ Get the force field parameters for an angle term.
- Parameters
index (int) – the index of the angle for which to get parameters
- Returns
particle1 (int) – the index of the first particle connected by the angle
particle2 (int) – the index of the second particle connected by the angle
particle3 (int) – the index of the third particle connected by the angle
particle4 (int) – the index of the fourth particle connected by the angle
length (double) – the equilibrium angle, measured in radians
quadraticK (double) – the quadratic force constant for the angle measured in kJ/mol/radian^2
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setAngleParameters
(self, index, particle1, particle2, particle3, particle4, length, quadraticK)¶ Set the force field parameters for an angle term.
- Parameters
index (int) – the index of the angle for which to set parameters
particle1 (int) – the index of the first particle connected by the angle
particle2 (int) – the index of the second particle connected by the angle
particle3 (int) – the index of the third particle connected by the angle
particle4 (int) – the index of the fourth particle connected by the angle
length (double) – the equilibrium angle, measured in radians
quadraticK (double) – the quadratic force constant for the angle, measured in kJ/mol/radian^2
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updateParametersInContext
(self, 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 updateParametersInContext() 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.
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setUsesPeriodicBoundaryConditions
(self, 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.
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usesPeriodicBoundaryConditions
(self) → bool¶ Returns whether or not this force makes use of periodic boundary conditions.
- Returns
true if force uses PBC and false otherwise
- Return type
bool
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__copy__
(self) → Force¶
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getForceGroup
(self) → int¶ Get the force group this Force belongs to.
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setForceGroup
(self, group)¶ Set the force group this Force belongs to.
- Parameters
group (int) – the group index. Legal values are between 0 and 31 (inclusive).
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