lennardJones.C

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    Copyright (C) 2011 OpenFOAM Foundation
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License
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#include "lennardJones.H"
#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{
namespace pairPotentials
{

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

defineTypeNameAndDebug(lennardJones, 0);

addToRunTimeSelectionTable
(
    pairPotential,
    lennardJones,
    dictionary
);


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

lennardJones::lennardJones
(
    const word& name,
    const dictionary& pairPotentialProperties
)
:
    pairPotential(name, pairPotentialProperties),
    lennardJonesCoeffs_(pairPotentialProperties.subDict(typeName + "Coeffs")),
    sigma_(lennardJonesCoeffs_.get<scalar>("sigma")),
    epsilon_(lennardJonesCoeffs_.get<scalar>("epsilon"))
{
    setLookupTables();
}


// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //

scalar lennardJones::unscaledEnergy(const scalar r) const
{
    // (rIJ/sigma)^-2
    scalar ir2 = (sigma_/r)*(sigma_/r);

    // (rIJ/sigma)^-6
    scalar ir6 = ir2*ir2*ir2;

    return 4.0 * epsilon_*(ir6*(ir6 - 1.0));
}


bool lennardJones::read(const dictionary& pairPotentialProperties)
{
    pairPotential::read(pairPotentialProperties);

    lennardJonesCoeffs_ = pairPotentialProperties.subDict(typeName + "Coeffs");

    lennardJonesCoeffs_.readEntry("sigma", sigma_);
    lennardJonesCoeffs_.readEntry("epsilon", epsilon_);

    return true;
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace pairPotentials
} // End namespace Foam

// ************************************************************************* //