| 1 | 
/* | 
| 2 | 
 * Copyright (c) 2005 The University of Notre Dame. All Rights Reserved. | 
| 3 | 
 * | 
| 4 | 
 * The University of Notre Dame grants you ("Licensee") a | 
| 5 | 
 * non-exclusive, royalty free, license to use, modify and | 
| 6 | 
 * redistribute this software in source and binary code form, provided | 
| 7 | 
 * that the following conditions are met: | 
| 8 | 
 * | 
| 9 | 
 * 1. Redistributions of source code must retain the above copyright | 
| 10 | 
 *    notice, this list of conditions and the following disclaimer. | 
| 11 | 
 * | 
| 12 | 
 * 2. Redistributions in binary form must reproduce the above copyright | 
| 13 | 
 *    notice, this list of conditions and the following disclaimer in the | 
| 14 | 
 *    documentation and/or other materials provided with the | 
| 15 | 
 *    distribution. | 
| 16 | 
 * | 
| 17 | 
 * This software is provided "AS IS," without a warranty of any | 
| 18 | 
 * kind. All express or implied conditions, representations and | 
| 19 | 
 * warranties, including any implied warranty of merchantability, | 
| 20 | 
 * fitness for a particular purpose or non-infringement, are hereby | 
| 21 | 
 * excluded.  The University of Notre Dame and its licensors shall not | 
| 22 | 
 * be liable for any damages suffered by licensee as a result of | 
| 23 | 
 * using, modifying or distributing the software or its | 
| 24 | 
 * derivatives. In no event will the University of Notre Dame or its | 
| 25 | 
 * licensors be liable for any lost revenue, profit or data, or for | 
| 26 | 
 * direct, indirect, special, consequential, incidental or punitive | 
| 27 | 
 * damages, however caused and regardless of the theory of liability, | 
| 28 | 
 * arising out of the use of or inability to use software, even if the | 
| 29 | 
 * University of Notre Dame has been advised of the possibility of | 
| 30 | 
 * such damages. | 
| 31 | 
 * | 
| 32 | 
 * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your | 
| 33 | 
 * research, please cite the appropriate papers when you publish your | 
| 34 | 
 * work.  Good starting points are: | 
| 35 | 
 *                                                                       | 
| 36 | 
 * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).              | 
| 37 | 
 * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).           | 
| 38 | 
 * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008).           | 
| 39 | 
 * [4]  Kuang & Gezelter,  J. Chem. Phys. 133, 164101 (2010). | 
| 40 | 
 * [5]  Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011). | 
| 41 | 
 */ | 
| 42 | 
#include "perturbations/ElectricField.hpp" | 
| 43 | 
#include "types/FixedChargeAdapter.hpp" | 
| 44 | 
#include "types/FluctuatingChargeAdapter.hpp" | 
| 45 | 
#include "types/MultipoleAdapter.hpp" | 
| 46 | 
#include "primitives/Molecule.hpp" | 
| 47 | 
#include "nonbonded/NonBondedInteraction.hpp" | 
| 48 | 
 | 
| 49 | 
namespace OpenMD { | 
| 50 | 
 | 
| 51 | 
  ElectricField::ElectricField(SimInfo* info) : info_(info),  | 
| 52 | 
                                                doElectricField(false),  | 
| 53 | 
                                                doParticlePot(false), | 
| 54 | 
                                                initialized(false) { | 
| 55 | 
    simParams = info_->getSimParams(); | 
| 56 | 
  } | 
| 57 | 
 | 
| 58 | 
  void ElectricField::initialize() { | 
| 59 | 
    if (simParams->haveElectricField()) { | 
| 60 | 
      doElectricField = true; | 
| 61 | 
      EF = simParams->getElectricField(); | 
| 62 | 
    }    | 
| 63 | 
    int storageLayout_ = info_->getSnapshotManager()->getStorageLayout(); | 
| 64 | 
    if (storageLayout_ & DataStorage::dslParticlePot) doParticlePot = true; | 
| 65 | 
    initialized = true; | 
| 66 | 
  } | 
| 67 | 
 | 
| 68 | 
  void ElectricField::applyPerturbation() { | 
| 69 | 
    if (!initialized) initialize(); | 
| 70 | 
 | 
| 71 | 
    SimInfo::MoleculeIterator i; | 
| 72 | 
    Molecule::AtomIterator  j; | 
| 73 | 
    Molecule* mol; | 
| 74 | 
    Atom* atom; | 
| 75 | 
    potVec longRangePotential(0.0); | 
| 76 | 
    Vector3d dip; | 
| 77 | 
    Vector3d trq; | 
| 78 | 
    Vector3d EFfrc;                              | 
| 79 | 
    Vector3d pos; | 
| 80 | 
    RealType chrg; | 
| 81 | 
    RealType pot, fieldPot; | 
| 82 | 
    RealType chrgToKcal = 23.0609; | 
| 83 | 
    RealType debyeToKcal = 4.8018969509; | 
| 84 | 
 | 
| 85 | 
 | 
| 86 | 
    if (doElectricField) { | 
| 87 | 
      fieldPot = 0.0; | 
| 88 | 
 | 
| 89 | 
      for (mol = info_->beginMolecule(i); mol != NULL;  | 
| 90 | 
           mol = info_->nextMolecule(i)) {       | 
| 91 | 
 | 
| 92 | 
        for (atom = mol->beginAtom(j); atom != NULL; | 
| 93 | 
             atom = mol->nextAtom(j)) { | 
| 94 | 
 | 
| 95 | 
          bool isCharge = false; | 
| 96 | 
          chrg = 0.0; | 
| 97 | 
           | 
| 98 | 
          AtomType* atype = atom->getAtomType(); | 
| 99 | 
           | 
| 100 | 
          if (atype->isElectrostatic()) { | 
| 101 | 
            atom->addElectricField(EF * chrgToKcal); | 
| 102 | 
          } | 
| 103 | 
           | 
| 104 | 
          FixedChargeAdapter fca = FixedChargeAdapter(atype); | 
| 105 | 
          if ( fca.isFixedCharge() ) { | 
| 106 | 
            isCharge = true; | 
| 107 | 
            chrg = fca.getCharge(); | 
| 108 | 
          } | 
| 109 | 
           | 
| 110 | 
          FluctuatingChargeAdapter fqa = FluctuatingChargeAdapter(atype); | 
| 111 | 
          if ( fqa.isFluctuatingCharge() ) { | 
| 112 | 
            isCharge = true; | 
| 113 | 
            chrg += atom->getFlucQPos(); | 
| 114 | 
          } | 
| 115 | 
           | 
| 116 | 
          if (isCharge) { | 
| 117 | 
            EFfrc = EF*chrg; | 
| 118 | 
            EFfrc *= chrgToKcal; | 
| 119 | 
            atom->addFrc(EFfrc); | 
| 120 | 
            // ad-hoc choice of the origin for potential calculation | 
| 121 | 
            pos = atom->getPos(); | 
| 122 | 
            pot = -dot(pos, EFfrc); | 
| 123 | 
            if (doParticlePot) {       | 
| 124 | 
              atom->addParticlePot(pot); | 
| 125 | 
            } | 
| 126 | 
            fieldPot += pot; | 
| 127 | 
          } | 
| 128 | 
             | 
| 129 | 
          MultipoleAdapter ma = MultipoleAdapter(atype); | 
| 130 | 
          if (ma.isDipole() ) { | 
| 131 | 
            Vector3d dipole = atom->getDipole(); | 
| 132 | 
            dipole *= debyeToKcal; | 
| 133 | 
 | 
| 134 | 
            trq = cross(dipole, EF); | 
| 135 | 
            atom->addTrq(trq); | 
| 136 | 
 | 
| 137 | 
            pot = -dot(dipole, EF); | 
| 138 | 
            if (doParticlePot) {       | 
| 139 | 
              atom->addParticlePot(pot); | 
| 140 | 
            } | 
| 141 | 
            fieldPot += pot; | 
| 142 | 
          } | 
| 143 | 
        } | 
| 144 | 
      } | 
| 145 | 
#ifdef IS_MPI | 
| 146 | 
      MPI::COMM_WORLD.Allreduce(MPI::IN_PLACE, &fieldPot, 1, MPI::REALTYPE,  | 
| 147 | 
                                MPI::SUM); | 
| 148 | 
#endif | 
| 149 | 
      Snapshot* snap = info_->getSnapshotManager()->getCurrentSnapshot(); | 
| 150 | 
      longRangePotential = snap->getLongRangePotentials(); | 
| 151 | 
      longRangePotential[ELECTROSTATIC_FAMILY] += fieldPot; | 
| 152 | 
      snap->setLongRangePotential(longRangePotential); | 
| 153 | 
    } | 
| 154 | 
  } | 
| 155 | 
} |