Package etomica.potential

Class P2Ideal

java.lang.Object

etomica.potential.Potential

etomica.potential.Potential2

etomica.potential.P2Ideal

All Implemented Interfaces:

IPotential, IPotentialAtomic, Potential2Soft, Potential2Spherical, PotentialHard, PotentialSoft

public class P2Ideal
extends Potential2
implements Potential2Soft, Potential2Spherical, PotentialHard

Ideal-gas two-body potential, which defines no interactions and zero energy for all pairs given to it.

Useful as a placeholder where a potential is expected but it is desired to not have the atoms interact.

Field Summary

Fields

Modifier and Type	Field	Description
protected double	range

Fields inherited from class etomica.potential.Potential

space

Constructor Summary

Constructors

Constructor	Description
P2Ideal(Space space)

Method Summary

Modifier and Type	Method	Description
void	bump(IAtomList atom, double falseTime)	Does nothing.
double	collisionTime(IAtomList atom, double falseTime)	Returns Double.POSITIVE_INFINITY.
double	du(double r2)	Returns zero.
double	energy(IAtomList atoms)	Returns zero.
double	energyChange()	Returns zero.
double	getRange()	Returns zero.
Vector[]	gradient(IAtomList atoms)	Returns a zero vector.
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.
double	hyperVirial(IAtomList pair)	Returns zero.
double	integral(double rC)	Returns zero.
double	lastCollisionVirial()	Returns zero.
Tensor	lastCollisionVirialTensor()	Returns a tensor of zeros.
void	setBox(Box box)	Does nothing.
void	setRange(double range)
double	u(double r2)	Returns zero.
double	virial(IAtomList pair)	Returns zero.

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

range

protected double range

Constructor Detail

P2Ideal

public P2Ideal(Space space)

Method Detail

setBox

public void setBox(Box box)

Does nothing.

Specified by:

setBox in interface IPotential

Specified by:

setBox in class Potential

setRange

public void setRange(double range)

getRange

public double getRange()

Returns zero.

Specified by:

getRange in interface IPotential

Specified by:

getRange in class Potential

energy

public double energy(IAtomList atoms)

Returns zero.

Specified by:

energy in interface IPotentialAtomic

Specified by:

energy in class Potential

hyperVirial

public double hyperVirial(IAtomList pair)

Returns zero.

Specified by:

hyperVirial in interface Potential2Soft

virial

public double virial(IAtomList pair)

Returns zero.

Specified by:

virial in interface PotentialSoft

integral

public double integral(double rC)

Returns zero.

Specified by:

integral in interface Potential2Soft

u

public double u(double r2)

Returns zero.

Specified by:

u in interface Potential2Spherical

Parameters:

r2 - the square of the distance between the particles.

du

public double du(double r2)

Returns zero.

Specified by:

du in interface Potential2Soft

lastCollisionVirial

public double lastCollisionVirial()

Returns zero.

Specified by:

lastCollisionVirial in interface PotentialHard

Returns:

double virial value

lastCollisionVirialTensor

public Tensor lastCollisionVirialTensor()

Returns a tensor of zeros.

Specified by:

lastCollisionVirialTensor in interface PotentialHard

Returns:

Tensor

bump

public void bump(IAtomList atom,
                 double falseTime)

Does nothing.

Specified by:

bump in interface PotentialHard

collisionTime

public double collisionTime(IAtomList atom,
                            double falseTime)

Returns Double.POSITIVE_INFINITY.

Specified by:

collisionTime in interface PotentialHard

energyChange

public double energyChange()

Returns zero.

Specified by:

energyChange in interface PotentialHard

gradient

public Vector[] gradient(IAtomList atoms)

Returns a zero vector.

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