Package etomica.potential

Class P2PenetrableSphere

java.lang.Object

etomica.potential.Potential

etomica.potential.Potential2

etomica.potential.Potential2HardSpherical

etomica.potential.P2PenetrableSphere

All Implemented Interfaces:

IPotential, IPotentialAtomic, Potential2Spherical, PotentialHard

public class P2PenetrableSphere
extends Potential2HardSpherical

Basic penetrable-sphere potential. Energy is epsilon if spheres overlap, and is zero otherwise. Core diameter describes height of penetrable core. Suitable for use in space of any dimension. Can be used with negative value for epsilon to produce a square-well potential with no hard core.

Field Summary

Fields

Modifier and Type	Field	Description
protected double	coreDiameter
protected double	coreDiameterSquared
protected Vector	dv
protected double	epsilon
protected double	lastCollisionVirial
protected double	lastCollisionVirialr2
protected Tensor	lastCollisionVirialTensor
protected double	lastEnergyChange

Fields inherited from class etomica.potential.Potential

space

Fields inherited from class etomica.potential.Potential2HardSpherical

boundary, dr

Constructor Summary

Constructors

Constructor	Description
P2PenetrableSphere(Space space)	Constructor with default values of unity for core diameter and core energy.
P2PenetrableSphere(Space space, double coreDiameter, double epsilon)

Method Summary

Modifier and Type	Method	Description
void	bump(IAtomList pair, double falseTime)	Implements collision dynamics between two penetrable-sphere atoms.
double	collisionTime(IAtomList pair, double falseTime)	Computes next time of collision of two square-well atoms, assuming free-flight kinematics.
double	energyChange()	returns change in potential energy due to the last collision
double	getCoreDiameter()	Accessor method for core diameter.
Dimension	getCoreDiameterDimension()
double	getEpsilon()	Mutator method for height of core.
Dimension	getEpsilonDimension()
double	getRange()	Returns the range over which the potential applies.
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	setCoreDiameter(double c)	Mutator method for core diameter.
void	setEpsilon(double eps)	Accessor method for height of core.
double	u(double r2)	Returns epsilon if overlapping, or zero if not.

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

Methods inherited from class etomica.potential.Potential2HardSpherical

energy, setBox

Field Detail

coreDiameter

protected double coreDiameter

coreDiameterSquared

protected double coreDiameterSquared

epsilon

protected double epsilon

lastCollisionVirial

protected double lastCollisionVirial

lastCollisionVirialr2

protected double lastCollisionVirialr2

lastCollisionVirialTensor

protected Tensor lastCollisionVirialTensor

lastEnergyChange

protected double lastEnergyChange

dv

protected Vector dv

Constructor Detail

P2PenetrableSphere

public P2PenetrableSphere(Space space)

Constructor with default values of unity for core diameter and core energy.

P2PenetrableSphere

public P2PenetrableSphere(Space space,
                          double coreDiameter,
                          double epsilon)

Method Detail

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

bump

public void bump(IAtomList pair,
                 double falseTime)

Implements collision dynamics between two penetrable-sphere atoms.

lastCollisionVirial

public double lastCollisionVirial()

Description copied from interface: PotentialHard

Value of the virial from the most recent collision.

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.

Returns:

Tensor

collisionTime

public double collisionTime(IAtomList pair,
                            double falseTime)

Computes next time of collision of two square-well atoms, assuming free-flight kinematics. Collision may occur when cores collides, or when wells first encounter each other on approach, or when they edge of the wells are reached as atoms diverge.

u

public double u(double r2)

Returns epsilon if overlapping, or zero if not.

Specified by:

u in interface Potential2Spherical

Specified by:

u in class Potential2HardSpherical

Parameters:

r2 - the square of the distance between the particles.

energyChange

public double energyChange()

Description copied from interface: PotentialHard

returns change in potential energy due to the last collision

getCoreDiameter

public double getCoreDiameter()

Accessor method for core diameter.

setCoreDiameter

public void setCoreDiameter(double c)

Mutator method for core diameter.

getCoreDiameterDimension

public Dimension getCoreDiameterDimension()

getEpsilon

public double getEpsilon()

Mutator method for height of core.

setEpsilon

public void setEpsilon(double eps)

Accessor method for height of core. Positive value corresponds to a positive core height.

getEpsilonDimension

public Dimension getEpsilonDimension()