Package etomica.potential

Class Potential0Lrc

java.lang.Object

etomica.potential.Potential

etomica.potential.Potential0

etomica.potential.Potential0Lrc

All Implemented Interfaces:

IPotential, IPotential0Lrc, IPotentialAtomic, PotentialSoft

Direct Known Subclasses:

P2SoftSphericalTruncated.P0Lrc

public abstract class Potential0Lrc
extends Potential0
implements PotentialSoft, IPotential0Lrc

Zero-body potential implementing the long-range correction that compensates for truncation of the potential. Normally, the concrete instance of this class is defined as an inner class to a PotentialTruncation class. The PotentialTruncation class defines the scheme used to truncate the potential, and its inner Potential0Lrc subclass implements the formulas needed to integrate the potential and its derivatives over the range affected by the truncation.
The components and procedures related to the long-range correction are as follows. The Potential2 constructor defines a PotentialTruncation that determines whether and how the pair potential may be truncated. If the PotentialTruncation is not passed as a parameter to the constructor, a default is used as indicated by the Default.TRUNCATE_POTENTIALS boolean flag. By default, all pair potentials are truncated using the PotentialTruncationSimple scheme; if TRUNCATE_POTENTIALS is set to false, the PotentialTruncation.Null truncation is applied to all new pair potentials. The PotentialTruncation for a potential cannot be changed after the potential is instantiated.
Each PotentialTruncation class defines an inner Potential0Lrc subclass that provides the appropriate methods for computing the long-range correction to the energy and its first two derivatives. This class is instantiated by the PotentialTruncation class in its constructor. Upon its instantiation, the Potential0Lrc class is added to the group of long-range correction potentials that is kept by a single Potential0GroupLrc instance in the PotentialMaster.
Before the calculate method of PotentialMaster is called to compute something, its set(Box) method must have been previously called, which identifies to all potentials (including Potential0GroupLrc) which box is subject to the ensuing calculation. Potential0Group ignores this notification if the given box is the same as the one specified in the previous call; otherwise it passes the identified box to all the set(Box) methods (inherited from Potential0) of the Potential0Lrc classes it holds.
Then when the calculate(IteratorDirective, PotentialCalculation) method of PotentialMaster is invoked, it passes the call on to the calculate methods of its child potentials, including the Potential0GroupLrc instance if present. Potential0GroupLrc checks that a box has been specified, that its enableLrc flag is true (the default), and that the given iteratorDirective's includeP0Lrc flag is also true (default is false). If so, it calls the calculate methods of all child Potential0Lrc classes. The Potential0Lrc class will use the volume from the specified box and the size method of the iterator of its associated potential to determine the pair density. The Potential0Lrc methods are called if the PotentialCalculation implements Potential0Calculation.

Field Summary

Fields

Modifier and Type	Field	Description
protected Box	box
protected double	divisor
protected boolean	interType
protected int[]	lrcAtomsPerMolecule
protected IPotentialAtomic	truncatedPotential
protected AtomType[]	types

Fields inherited from class etomica.potential.Potential

space

Constructor Summary

Constructors

Constructor	Description
Potential0Lrc(Space space, AtomType[] types, IPotentialAtomic truncatedPotential)

Method Summary

Modifier and Type	Method	Description
IPotentialAtomic	getTruncatedPotential()	Returns the potential whose truncation this lrcPotential exists to correct.
protected long	nPairs()	Returns the number of pairs formed from molecules of the current species, in the given box.
void	setBox(Box b)	Informs the potential of the box on which it acts.
void	setTargetAtom(IAtom targetAtom)	Informs the potential of a target atom.
void	setTargetMolecule(IMolecule targetAtom)	Informs the potential of a target atom.

Methods inherited from interface etomica.potential.IPotential

getRange, nBody

Methods inherited from interface etomica.potential.IPotentialAtomic

energy

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

energy, nBody

Methods inherited from class etomica.potential.Potential0

getCriterion, getRange

Methods inherited from interface etomica.potential.PotentialSoft

gradient, gradient, virial

Field Detail

types

protected final AtomType[] types

interType

protected final boolean interType

truncatedPotential

protected final IPotentialAtomic truncatedPotential

lrcAtomsPerMolecule

protected final int[] lrcAtomsPerMolecule

divisor

protected double divisor

box

protected Box box

Constructor Detail

Potential0Lrc

public Potential0Lrc(Space space,
                     AtomType[] types,
                     IPotentialAtomic truncatedPotential)

Method Detail

getTruncatedPotential

public IPotentialAtomic getTruncatedPotential()

Returns the potential whose truncation this lrcPotential exists to correct.

setBox

public void setBox(Box b)

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

setTargetAtom

public void setTargetAtom(IAtom targetAtom)

Description copied from interface: IPotential0Lrc

Informs the potential of a target atom. Null target atom indicates no target atom.

Specified by:

setTargetAtom in interface IPotential0Lrc

setTargetMolecule

public void setTargetMolecule(IMolecule targetAtom)

Description copied from interface: IPotential0Lrc

Informs the potential of a target atom. Null target atom indicates no target atom.

Specified by:

setTargetMolecule in interface IPotential0Lrc

nPairs

protected long nPairs()

Returns the number of pairs formed from molecules of the current species, in the given box.

Returns:

int