src/lagrangian/molecularDynamics/potential/pairPotential/derived/lennardJones/lennardJones.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
   3   \\      /  F ield         | foam-extend: Open Source CFD
   4    \\    /   O peration     | Version:     3.2
   5     \\  /    A nd           | Web:         http://www.foam-extend.org
   6      \\/     M anipulation  | For copyright notice see file Copyright
   7 -------------------------------------------------------------------------------
   8 License
   9     This file is part of foam-extend.
  10
  11     foam-extend is free software: you can redistribute it and/or modify it
  12     under the terms of the GNU General Public License as published by the
  13     Free Software Foundation, either version 3 of the License, or (at your
  14     option) any later version.
  15
  16     foam-extend is distributed in the hope that it will be useful, but
  17     WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19     General Public License for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 \*---------------------------------------------------------------------------*/
  25
  26 #include "lennardJones.H"
  27 #include "addToRunTimeSelectionTable.H"
  28
  29 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  30
  31 namespace Foam
  32 {
  33 namespace pairPotentials
  34 {
  35
  36 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  37
  38 defineTypeNameAndDebug(lennardJones, 0);
  39
  40 addToRunTimeSelectionTable
  41 (
  42     pairPotential,
  43     lennardJones,
  44     dictionary
  45 );
  46
  47
  48 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  49
  50 lennardJones::lennardJones
  51 (
  52     const word& name,
  53     const dictionary& pairPotentialProperties
  54 )
  55 :
  56     pairPotential(name, pairPotentialProperties),
  57     lennardJonesCoeffs_(pairPotentialProperties.subDict(typeName + "Coeffs")),
  58     sigma_(readScalar(lennardJonesCoeffs_.lookup("sigma"))),
  59     epsilon_(readScalar(lennardJonesCoeffs_.lookup("epsilon")))
  60 {
  61     setLookupTables();
  62 }
  63
  64
  65 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
  66
  67 scalar lennardJones::unscaledEnergy(const scalar r) const
  68 {
  69     // (rIJ/sigma)^-2
  70     scalar ir2 = (sigma_/r)*(sigma_/r);
  71
  72     // (rIJ/sigma)^-6
  73     scalar ir6 = ir2*ir2*ir2;
  74
  75     return 4.0 * epsilon_*(ir6*(ir6 - 1.0));
  76 }
  77
  78
  79 bool lennardJones::read(const dictionary& pairPotentialProperties)
  80 {
  81     pairPotential::read(pairPotentialProperties);
  82
  83     lennardJonesCoeffs_ = pairPotentialProperties.subDict(typeName + "Coeffs");
  84
  85     lennardJonesCoeffs_.lookup("sigma") >> sigma_;
  86     lennardJonesCoeffs_.lookup("epsilon") >> epsilon_;
  87
  88     return true;
  89 }
  90
  91
  92 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  93
  94 } // End namespace pairPotentials
  95 } // End namespace Foam
  96
  97 // ************************************************************************* //