Package etomica.normalmode

Class P2XOrder

java.lang.Object

etomica.potential.Potential

etomica.potential.Potential2

etomica.normalmode.P2XOrder

All Implemented Interfaces:

IPotential, IPotentialAtomic, Potential2Spherical, PotentialHard

public class P2XOrder
extends Potential2
implements Potential2Spherical, PotentialHard

Hard potential that enforces ordering of the x-coordinates of the pairs. Returns infinite energy if the difference in atom indexes and difference in x coordinates are of opposite sign; returns zero otherwise. Designed for use in 1D simulations.

Field Summary

Fields

Modifier and Type	Field	Description
protected Box	box
protected Vector	dr
protected boolean	hasPBC
protected Potential2HardSpherical	wrappedPotential

Fields inherited from class etomica.potential.Potential

space

Constructor Summary

Constructors

Constructor	Description
P2XOrder(Space space, Potential2HardSpherical wrappedPotential)

Method Summary

Modifier and Type	Method	Description
void	bump(IAtomList atom, double falseTime)	Implements the collision dynamics.
double	collisionTime(IAtomList atom, double falseTime)	Computes the time of collision of the given atom(s) with the hard potential, assuming no intervening collisions.
double	energy(IAtomList pair)	Interaction energy of the pair.
double	energyChange()	returns change in potential energy due to the last collision
double	getRange()	Returns infinity.
Potential2Spherical	getWrappedPotential()
double	lastCollisionVirial()	Value of the virial from the most recent collision.
Tensor	lastCollisionVirialTensor()	Value of the virial from the most recent collision, decomposed into it tensoral elements.
void	setBox(Box newBox)	Informs the potential of the box on which it acts.
double	u(double r2)	The pair energy u(r^2) with no truncation applied.

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

dr

protected final Vector dr

box

protected Box box

wrappedPotential

protected Potential2HardSpherical wrappedPotential

hasPBC

protected boolean hasPBC

Constructor Detail

P2XOrder

public P2XOrder(Space space,
                Potential2HardSpherical wrappedPotential)

Method Detail

energy

public double energy(IAtomList pair)

Interaction energy of the pair. Zero if x coordinates are ordered differently from atom indexes.

Specified by:

energy in interface IPotentialAtomic

Specified by:

energy in class Potential

getRange

public double getRange()

Returns infinity.

Specified by:

getRange in interface IPotential

Specified by:

getRange in class Potential

getWrappedPotential

public Potential2Spherical getWrappedPotential()

setBox

public void setBox(Box newBox)

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

bump

public void bump(IAtomList atom,
                 double falseTime)

Description copied from interface: PotentialHard

Implements the collision dynamics. The given atom(s) is assumed to be at the point of collision. This method is called to change their momentum according to the action of the collision. Extensions can be defined to instead implement other, perhaps unphysical changes.

Specified by:

bump in interface PotentialHard

collisionTime

public double collisionTime(IAtomList atom,
                            double falseTime)

Description copied from interface: PotentialHard

Computes the time of collision of the given atom(s) with the hard potential, assuming no intervening collisions. Usually assumes free-flight between collisions.

Specified by:

collisionTime in interface PotentialHard

energyChange

public double energyChange()

Description copied from interface: PotentialHard

returns change in potential energy due to the last collision

Specified by:

energyChange in interface PotentialHard

lastCollisionVirial

public double lastCollisionVirial()

Description copied from interface: PotentialHard

Value of the virial from the most recent collision.

Specified by:

lastCollisionVirial in interface PotentialHard

Returns:

double virial value

lastCollisionVirialTensor

public Tensor lastCollisionVirialTensor()

Description copied from interface: PotentialHard

Value of the virial from the most recent collision, decomposed into it tensoral elements.

Specified by:

lastCollisionVirialTensor in interface PotentialHard

Returns:

Tensor

u

public double u(double r2)

Description copied from interface: Potential2Spherical

The pair energy u(r^2) with no truncation applied.

Specified by:

u in interface Potential2Spherical

Parameters:

r2 - the square of the distance between the particles.