Package etomica.potential

Class P4BondTorsionAlkaneXCCH

java.lang.Object

etomica.potential.Potential

etomica.potential.P4BondTorsionAlkaneXCCH

All Implemented Interfaces:

IPotential, IPotentialAtomic, PotentialSoft

public class P4BondTorsionAlkaneXCCH
extends Potential
implements PotentialSoft

slight modification from P4BondTorsion class(change energyAtAngle method) Siepmann's Alkane TraPPE-EH model, XCCH torsion potential, X can be H or C, H is for H on CH3 only U(torsion) = Cx * (1 -cos(3phi)); C(C):854K, C(H):717K

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
P4BondTorsionAlkaneXCCH(Space space, double a0, double a1, double a2, double a3)

Method Summary

Modifier and Type	Method	Description
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

P4BondTorsionAlkaneXCCH

public P4BondTorsionAlkaneXCCH(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:

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)