Package etomica.spin.ising

Class P2Spin

java.lang.Object

etomica.potential.Potential

etomica.potential.Potential2

etomica.spin.ising.P2Spin

All Implemented Interfaces:

IPotential, IPotentialAtomic

public class P2Spin
extends Potential2

Magnetic spin potential, with an energy defined by

U = -J r1 dot r2

where J is a coupling parameter, and r1 and r2 are the vectors given by atom.coord.position. It is expected (but not verified here) that these vectors are normalized to unity, and that the simulation integrator's algorithm enforces this constraint.

Field Summary

Fields inherited from class etomica.potential.Potential

space

Constructor Summary

Constructors

Constructor	Description
P2Spin(Space space)
P2Spin(Space space, double coupling)

Method Summary

Modifier and Type	Method	Description
double	energy(IAtomList atoms)	Returns the energy for the given pair of atoms.
double	getCoupling()
double	getRange()	Returns 0, becuase potential operates on a lattice and range should not be needed.
void	setBox(Box box)	Informs the potential of the box on which it acts.
void	setCoupling(double coupling)

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

Constructor Detail

P2Spin

public P2Spin(Space space)

P2Spin

public P2Spin(Space space,
              double coupling)

Method Detail

energy

public double energy(IAtomList atoms)

Returns the energy for the given pair of atoms.

Specified by:

energy in interface IPotentialAtomic

Specified by:

energy in class Potential

Throws:

java.lang.ClassCastException - if atoms is not an instance of AtomPair

getRange

public double getRange()

Returns 0, becuase potential operates on a lattice and range should not be needed. The PotentialMasterSite expects all Potentials to have a range and uses the return value to determine whether or not to use site iteration.

Specified by:

getRange in interface IPotential

Specified by:

getRange in class Potential

getCoupling

public double getCoupling()

Returns:

Returns the coupling.

setCoupling

public void setCoupling(double coupling)

Parameters:

coupling - The coupling to set.

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