P4BondTorsion

java.lang.Object
- etomica.potential.Potential
- - etomica.potential.P4BondTorsion

All Implemented Interfaces:

IPotential, IPotentialAtomic, PotentialSoft

Direct Known Subclasses:

P4BondTorsionOPLS
```
public class P4BondTorsion
extends Potential
implements PotentialSoft
```
Torsion potential. Jorgensen, W. L., Madura, J. D. and Swenson, C. J. J. Am. chem. Soc., 106, 6638-6646 (1984)

Field Summary

Fields
Modifier and Type	Field	Description
`protected double`	`a0`
`protected double`	`a1`
`protected double`	`a2`
`protected double`	`a3`
`protected Boundary`	`boundary`
`protected Vector`	`dr21`
`protected Vector`	`dr23`
`protected Vector`	`dr34`
`protected Vector[]`	`gradient`
`protected Vector`	`gtmp`
`protected Vector`	`v1`
`protected Vector`	`v2`

Fields inherited from class etomica.potential.Potential
space

Constructor Summary

Constructors
Constructor Description

P4BondTorsion(Space space, double a0, double a1, double a2, double a3)

Constructors
Constructor	Description
`P4BondTorsion(Space space, double a0, double a1, double a2, double a3)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double`	`dUdcosphi(double cosphi)`
`double`	`energy(IAtomList atomSet)`	Returns the interaction energy between the given atoms.
`double`	`energyAtAngle(double cosphi)`
`double`	`getRange()`	Returns the range over which the potential applies.
`Vector[]`	`gradient(IAtomList atoms)`	Returns the gradient of the potential as it applies to each atom in the given AtomSet, indicating how the energy would change as the position of the first atom is varied.
`Vector[]`	`gradient(IAtomList atoms, Tensor pressureTensor)`	Returns the same gradient as gradient(AtomSet) and also adds in the contribution of the AtomSet to the pressureTensor.
`static void`	`main(java.lang.String[] args)`
`void`	`setBox(Box box)`	Informs the potential of the box on which it acts.
`double`	`virial(IAtomList atoms)`

Methods inherited from interface etomica.potential.IPotential
nBody

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from class etomica.potential.Potential
nBody

- Field Detail
  - dr21
```
protected final Vector dr21
```
  - dr23
```
protected final Vector dr23
```
  - dr34
```
protected final Vector dr34
```
  - v1
```
protected final Vector v1
```
  - v2
```
protected final Vector v2
```
  - gtmp
```
protected final Vector gtmp
```
  - boundary
```
protected Boundary boundary
```
  - a0
```
protected double a0
```
  - a1
```
protected double a1
```
  - a2
```
protected double a2
```
  - a3
```
protected double a3
```
  - gradient
```
protected final Vector[] gradient
```
- Constructor Detail
  - P4BondTorsion
```
public P4BondTorsion(Space space,
                     double a0,
                     double a1,
                     double a2,
                     double a3)
```
- Method Detail
  - setBox
```
public void setBox(Box box)
```
    Description copied from class: Potential
    
    Informs the potential of the box on which it acts. Typically this requires at least that it update the nearestImageTransformer of its coordinatePair (if it uses one), e.g.: cPair.setNearestImageTransformer(box.boundary());
    
    Specified by:
    
    setBox in interface IPotential
    
    Specified by:
    
    setBox in class Potential
  - energy
```
public double energy(IAtomList atomSet)
```
    Description copied from class: Potential
    
    Returns the interaction energy between the given atoms. There might be 0, 1, 2 or more atoms in the AtomSet.
    
    Specified by:
    
    energy in interface IPotentialAtomic
    
    Specified by:
    
    energy in class Potential
  - energyAtAngle
```
public double energyAtAngle(double cosphi)
```
  - getRange
```
public double getRange()
```
    Description copied from interface: IPotential
    
    Returns the range over which the potential applies. IAtoms with a greater separation do not interact.
    
    Specified by:
    
    getRange in interface IPotential
    
    Specified by:
    
    getRange in class Potential
  - gradient
```
public Vector[] gradient(IAtomList atoms)
```
    Description copied from interface: PotentialSoft
    
    Returns the gradient of the potential as it applies to each atom in the given AtomSet, indicating how the energy would change as the position of the first atom is varied. The method is allowed to return an array of Vectors with fewer elements than the number of atoms in the AtomSet.
    
    Specified by:
    
    gradient in interface PotentialSoft
    
    Returns:
  - dUdcosphi
```
public double dUdcosphi(double cosphi)
```
  - gradient
```
public Vector[] gradient(IAtomList atoms,
                         Tensor pressureTensor)
```
    Description copied from interface: PotentialSoft
    
    Returns the same gradient as gradient(AtomSet) and also adds in the contribution of the AtomSet to the pressureTensor. Their contribution is added to the given Tensor. This combined method exists for computational efficiency. Calculating the pressureTensor is generally trivial once the gradient is known but often requires intermediate information.
    
    Specified by:
    
    gradient in interface PotentialSoft
  - virial
```
public double virial(IAtomList atoms)
```
    Specified by:
    
    virial in interface PotentialSoft
  - main
```
public static void main(java.lang.String[] args)
```

Class P4BondTorsion

Field Summary

Fields inherited from class etomica.potential.Potential

Constructor Summary

Method Summary

Methods inherited from interface etomica.potential.IPotential

Methods inherited from class java.lang.Object

Methods inherited from class etomica.potential.Potential

Field Detail

dr21

dr23

dr34

v1

v2

gtmp

boundary

a0

a1

a2

a3

gradient

Constructor Detail

P4BondTorsion

Method Detail

setBox

energy

energyAtAngle

getRange

gradient

dUdcosphi

gradient

virial

main