| 1 | gezelter | 246 | /* | 
| 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. Acknowledgement of the program authors must be made in any | 
| 10 |  |  | *    publication of scientific results based in part on use of the | 
| 11 |  |  | *    program.  An acceptable form of acknowledgement is citation of | 
| 12 |  |  | *    the article in which the program was described (Matthew | 
| 13 |  |  | *    A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher | 
| 14 |  |  | *    J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented | 
| 15 |  |  | *    Parallel Simulation Engine for Molecular Dynamics," | 
| 16 |  |  | *    J. Comput. Chem. 26, pp. 252-271 (2005)) | 
| 17 |  |  | * | 
| 18 |  |  | * 2. Redistributions of source code must retain the above copyright | 
| 19 |  |  | *    notice, this list of conditions and the following disclaimer. | 
| 20 |  |  | * | 
| 21 |  |  | * 3. Redistributions in binary form must reproduce the above copyright | 
| 22 |  |  | *    notice, this list of conditions and the following disclaimer in the | 
| 23 |  |  | *    documentation and/or other materials provided with the | 
| 24 |  |  | *    distribution. | 
| 25 |  |  | * | 
| 26 |  |  | * This software is provided "AS IS," without a warranty of any | 
| 27 |  |  | * kind. All express or implied conditions, representations and | 
| 28 |  |  | * warranties, including any implied warranty of merchantability, | 
| 29 |  |  | * fitness for a particular purpose or non-infringement, are hereby | 
| 30 |  |  | * excluded.  The University of Notre Dame and its licensors shall not | 
| 31 |  |  | * be liable for any damages suffered by licensee as a result of | 
| 32 |  |  | * using, modifying or distributing the software or its | 
| 33 |  |  | * derivatives. In no event will the University of Notre Dame or its | 
| 34 |  |  | * licensors be liable for any lost revenue, profit or data, or for | 
| 35 |  |  | * direct, indirect, special, consequential, incidental or punitive | 
| 36 |  |  | * damages, however caused and regardless of the theory of liability, | 
| 37 |  |  | * arising out of the use of or inability to use software, even if the | 
| 38 |  |  | * University of Notre Dame has been advised of the possibility of | 
| 39 |  |  | * such damages. | 
| 40 |  |  | */ | 
| 41 |  |  |  | 
| 42 |  |  | #include "integrators/NVT.hpp" | 
| 43 |  |  | #include "primitives/Molecule.hpp" | 
| 44 | tim | 3 | #include "utils/simError.h" | 
| 45 | gezelter | 246 | #include "utils/OOPSEConstant.hpp" | 
| 46 | gezelter | 2 |  | 
| 47 | gezelter | 246 | namespace oopse { | 
| 48 | gezelter | 2 |  | 
| 49 | tim | 270 | NVT::NVT(SimInfo* info) : VelocityVerletIntegrator(info), chiTolerance_ (1e-6), maxIterNum_(4) { | 
| 50 | gezelter | 2 |  | 
| 51 | gezelter | 246 | Globals* simParams = info_->getSimParams(); | 
| 52 | gezelter | 2 |  | 
| 53 | gezelter | 246 | if (simParams->getUseInitXSstate()) { | 
| 54 |  |  | Snapshot* currSnapshot = info_->getSnapshotManager()->getCurrentSnapshot(); | 
| 55 |  |  | currSnapshot->setChi(0.0); | 
| 56 |  |  | currSnapshot->setIntegralOfChiDt(0.0); | 
| 57 |  |  | } | 
| 58 |  |  |  | 
| 59 |  |  | if (!simParams->haveTargetTemp()) { | 
| 60 |  |  | sprintf(painCave.errMsg, "You can't use the NVT integrator without a targetTemp_!\n"); | 
| 61 |  |  | painCave.isFatal = 1; | 
| 62 |  |  | painCave.severity = OOPSE_ERROR; | 
| 63 |  |  | simError(); | 
| 64 |  |  | } else { | 
| 65 |  |  | targetTemp_ = simParams->getTargetTemp(); | 
| 66 |  |  | } | 
| 67 | gezelter | 2 |  | 
| 68 | gezelter | 246 | // We must set tauThermostat_. | 
| 69 | gezelter | 2 |  | 
| 70 | gezelter | 246 | if (!simParams->haveTauThermostat()) { | 
| 71 |  |  | sprintf(painCave.errMsg, "If you use the constant temperature\n" | 
| 72 |  |  | "\tintegrator, you must set tauThermostat_.\n"); | 
| 73 | gezelter | 2 |  | 
| 74 | gezelter | 246 | painCave.severity = OOPSE_ERROR; | 
| 75 |  |  | painCave.isFatal = 1; | 
| 76 |  |  | simError(); | 
| 77 |  |  | } else { | 
| 78 |  |  | tauThermostat_ = simParams->getTauThermostat(); | 
| 79 | gezelter | 2 | } | 
| 80 |  |  |  | 
| 81 | gezelter | 246 | update(); | 
| 82 | gezelter | 2 | } | 
| 83 |  |  |  | 
| 84 | gezelter | 246 | void NVT::doUpdate() { | 
| 85 |  |  | oldVel_.resize(info_->getNIntegrableObjects()); | 
| 86 |  |  | oldJi_.resize(info_->getNIntegrableObjects()); | 
| 87 | gezelter | 2 | } | 
| 88 | gezelter | 246 | void NVT::moveA() { | 
| 89 |  |  | SimInfo::MoleculeIterator i; | 
| 90 |  |  | Molecule::IntegrableObjectIterator  j; | 
| 91 |  |  | Molecule* mol; | 
| 92 |  |  | StuntDouble* integrableObject; | 
| 93 |  |  | Vector3d Tb; | 
| 94 |  |  | Vector3d ji; | 
| 95 |  |  | double mass; | 
| 96 |  |  | Vector3d vel; | 
| 97 |  |  | Vector3d pos; | 
| 98 |  |  | Vector3d frc; | 
| 99 | gezelter | 2 |  | 
| 100 | gezelter | 246 | double chi = currentSnapshot_->getChi(); | 
| 101 |  |  | double integralOfChidt = currentSnapshot_->getIntegralOfChiDt(); | 
| 102 |  |  |  | 
| 103 |  |  | // We need the temperature at time = t for the chi update below: | 
| 104 | gezelter | 2 |  | 
| 105 | gezelter | 246 | double instTemp = thermo.getTemperature(); | 
| 106 | gezelter | 2 |  | 
| 107 | gezelter | 246 | for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) { | 
| 108 |  |  | for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL; | 
| 109 |  |  | integrableObject = mol->nextIntegrableObject(j)) { | 
| 110 | gezelter | 2 |  | 
| 111 | gezelter | 246 | vel = integrableObject->getVel(); | 
| 112 |  |  | pos = integrableObject->getPos(); | 
| 113 |  |  | frc = integrableObject->getFrc(); | 
| 114 | gezelter | 2 |  | 
| 115 | gezelter | 246 | mass = integrableObject->getMass(); | 
| 116 | gezelter | 2 |  | 
| 117 | gezelter | 246 | // velocity half step  (use chi from previous step here): | 
| 118 |  |  | //vel[j] += dt2 * ((frc[j] / mass ) * OOPSEConstant::energyConvert - vel[j]*chi); | 
| 119 |  |  | vel += dt2 *OOPSEConstant::energyConvert/mass*frc - dt2*chi*vel; | 
| 120 |  |  |  | 
| 121 |  |  | // position whole step | 
| 122 |  |  | //pos[j] += dt * vel[j]; | 
| 123 |  |  | pos += dt * vel; | 
| 124 | gezelter | 2 |  | 
| 125 | gezelter | 246 | integrableObject->setVel(vel); | 
| 126 |  |  | integrableObject->setPos(pos); | 
| 127 | gezelter | 2 |  | 
| 128 | gezelter | 246 | if (integrableObject->isDirectional()) { | 
| 129 | gezelter | 2 |  | 
| 130 | gezelter | 246 | //convert the torque to body frame | 
| 131 |  |  | Tb = integrableObject->lab2Body(integrableObject->getTrq()); | 
| 132 | gezelter | 2 |  | 
| 133 | gezelter | 246 | // get the angular momentum, and propagate a half step | 
| 134 | gezelter | 2 |  | 
| 135 | gezelter | 246 | ji = integrableObject->getJ(); | 
| 136 | gezelter | 2 |  | 
| 137 | gezelter | 246 | //ji[j] += dt2 * (Tb[j] * OOPSEConstant::energyConvert - ji[j]*chi); | 
| 138 |  |  | ji += dt2*OOPSEConstant::energyConvert*Tb - dt2*chi *ji; | 
| 139 |  |  | rotAlgo->rotate(integrableObject, ji, dt); | 
| 140 | gezelter | 2 |  | 
| 141 | gezelter | 246 | integrableObject->setJ(ji); | 
| 142 |  |  | } | 
| 143 |  |  | } | 
| 144 | gezelter | 2 |  | 
| 145 |  |  | } | 
| 146 | gezelter | 246 |  | 
| 147 |  |  | rattle->constraintA(); | 
| 148 | gezelter | 2 |  | 
| 149 | gezelter | 246 | // Finally, evolve chi a half step (just like a velocity) using | 
| 150 |  |  | // temperature at time t, not time t+dt/2 | 
| 151 | gezelter | 2 |  | 
| 152 | gezelter | 246 |  | 
| 153 |  |  | chi += dt2 * (instTemp / targetTemp_ - 1.0) / (tauThermostat_ * tauThermostat_); | 
| 154 |  |  | integralOfChidt += chi * dt2; | 
| 155 | gezelter | 2 |  | 
| 156 | gezelter | 246 | currentSnapshot_->setChi(chi); | 
| 157 |  |  | currentSnapshot_->setIntegralOfChiDt(integralOfChidt); | 
| 158 | gezelter | 2 | } | 
| 159 |  |  |  | 
| 160 | gezelter | 246 | void NVT::moveB() { | 
| 161 |  |  | SimInfo::MoleculeIterator i; | 
| 162 |  |  | Molecule::IntegrableObjectIterator  j; | 
| 163 |  |  | Molecule* mol; | 
| 164 |  |  | StuntDouble* integrableObject; | 
| 165 |  |  |  | 
| 166 |  |  | Vector3d Tb; | 
| 167 |  |  | Vector3d ji; | 
| 168 |  |  | Vector3d vel; | 
| 169 |  |  | Vector3d frc; | 
| 170 |  |  | double mass; | 
| 171 |  |  | double instTemp; | 
| 172 |  |  | int index; | 
| 173 |  |  | // Set things up for the iteration: | 
| 174 | gezelter | 2 |  | 
| 175 | gezelter | 246 | double chi = currentSnapshot_->getChi(); | 
| 176 |  |  | double oldChi = chi; | 
| 177 |  |  | double  prevChi; | 
| 178 |  |  | double integralOfChidt = currentSnapshot_->getIntegralOfChiDt(); | 
| 179 | gezelter | 2 |  | 
| 180 | gezelter | 246 | index = 0; | 
| 181 |  |  | for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) { | 
| 182 |  |  | for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL; | 
| 183 |  |  | integrableObject = mol->nextIntegrableObject(j)) { | 
| 184 |  |  | oldVel_[index] = integrableObject->getVel(); | 
| 185 |  |  | oldJi_[index] = integrableObject->getJ(); | 
| 186 | gezelter | 2 |  | 
| 187 | gezelter | 246 | ++index; | 
| 188 |  |  | } | 
| 189 |  |  |  | 
| 190 | gezelter | 2 | } | 
| 191 |  |  |  | 
| 192 | gezelter | 246 | // do the iteration: | 
| 193 | gezelter | 2 |  | 
| 194 | gezelter | 246 | for(int k = 0; k < maxIterNum_; k++) { | 
| 195 |  |  | index = 0; | 
| 196 |  |  | instTemp = thermo.getTemperature(); | 
| 197 | gezelter | 2 |  | 
| 198 | gezelter | 246 | // evolve chi another half step using the temperature at t + dt/2 | 
| 199 | gezelter | 2 |  | 
| 200 | gezelter | 246 | prevChi = chi; | 
| 201 |  |  | chi = oldChi + dt2 * (instTemp / targetTemp_ - 1.0) / (tauThermostat_ * tauThermostat_); | 
| 202 | gezelter | 2 |  | 
| 203 | gezelter | 246 | for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) { | 
| 204 |  |  | for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL; | 
| 205 |  |  | integrableObject = mol->nextIntegrableObject(j)) { | 
| 206 | gezelter | 2 |  | 
| 207 | gezelter | 246 | frc = integrableObject->getFrc(); | 
| 208 |  |  | vel = integrableObject->getVel(); | 
| 209 | gezelter | 2 |  | 
| 210 | gezelter | 246 | mass = integrableObject->getMass(); | 
| 211 | gezelter | 2 |  | 
| 212 | gezelter | 246 | // velocity half step | 
| 213 |  |  | //for(j = 0; j < 3; j++) | 
| 214 |  |  | //    vel[j] = oldVel_[3*i+j] + dt2 * ((frc[j] / mass ) * OOPSEConstant::energyConvert - oldVel_[3*i + j]*chi); | 
| 215 |  |  | vel = oldVel_[index] + dt2/mass*OOPSEConstant::energyConvert * frc - dt2*chi*oldVel_[index]; | 
| 216 |  |  |  | 
| 217 |  |  | integrableObject->setVel(vel); | 
| 218 | gezelter | 2 |  | 
| 219 | gezelter | 246 | if (integrableObject->isDirectional()) { | 
| 220 | gezelter | 2 |  | 
| 221 | gezelter | 246 | // get and convert the torque to body frame | 
| 222 | gezelter | 2 |  | 
| 223 | gezelter | 246 | Tb =  integrableObject->lab2Body(integrableObject->getTrq()); | 
| 224 | gezelter | 2 |  | 
| 225 | gezelter | 246 | //for(j = 0; j < 3; j++) | 
| 226 |  |  | //    ji[j] = oldJi_[3*i + j] + dt2 * (Tb[j] * OOPSEConstant::energyConvert - oldJi_[3*i+j]*chi); | 
| 227 |  |  | ji = oldJi_[index] + dt2*OOPSEConstant::energyConvert*Tb - dt2*chi *oldJi_[index]; | 
| 228 | gezelter | 2 |  | 
| 229 | gezelter | 246 | integrableObject->setJ(ji); | 
| 230 |  |  | } | 
| 231 | gezelter | 2 |  | 
| 232 |  |  |  | 
| 233 | gezelter | 246 | ++index; | 
| 234 |  |  | } | 
| 235 |  |  | } | 
| 236 | gezelter | 2 |  | 
| 237 |  |  |  | 
| 238 | gezelter | 246 | rattle->constraintB(); | 
| 239 | gezelter | 2 |  | 
| 240 | gezelter | 246 | if (fabs(prevChi - chi) <= chiTolerance_) | 
| 241 |  |  | break; | 
| 242 | gezelter | 2 |  | 
| 243 | gezelter | 246 | } | 
| 244 | gezelter | 2 |  | 
| 245 | gezelter | 246 | integralOfChidt += dt2 * chi; | 
| 246 | gezelter | 2 |  | 
| 247 | gezelter | 246 | currentSnapshot_->setChi(chi); | 
| 248 |  |  | currentSnapshot_->setIntegralOfChiDt(integralOfChidt); | 
| 249 | gezelter | 2 | } | 
| 250 |  |  |  | 
| 251 |  |  |  | 
| 252 | gezelter | 246 | double NVT::calcConservedQuantity() { | 
| 253 | gezelter | 2 |  | 
| 254 | gezelter | 246 | double chi = currentSnapshot_->getChi(); | 
| 255 |  |  | double integralOfChidt = currentSnapshot_->getIntegralOfChiDt(); | 
| 256 |  |  | double conservedQuantity; | 
| 257 |  |  | double fkBT; | 
| 258 |  |  | double Energy; | 
| 259 |  |  | double thermostat_kinetic; | 
| 260 |  |  | double thermostat_potential; | 
| 261 |  |  |  | 
| 262 |  |  | fkBT = info_->getNdf() *OOPSEConstant::kB *targetTemp_; | 
| 263 | gezelter | 2 |  | 
| 264 | gezelter | 246 | Energy = thermo.getTotalE(); | 
| 265 | gezelter | 2 |  | 
| 266 | gezelter | 246 | thermostat_kinetic = fkBT * tauThermostat_ * tauThermostat_ * chi * chi / (2.0 * OOPSEConstant::energyConvert); | 
| 267 | gezelter | 2 |  | 
| 268 | gezelter | 246 | thermostat_potential = fkBT * integralOfChidt / OOPSEConstant::energyConvert; | 
| 269 | gezelter | 2 |  | 
| 270 | gezelter | 246 | conservedQuantity = Energy + thermostat_kinetic + thermostat_potential; | 
| 271 | gezelter | 2 |  | 
| 272 | gezelter | 246 | return conservedQuantity; | 
| 273 | gezelter | 2 | } | 
| 274 |  |  |  | 
| 275 |  |  |  | 
| 276 | gezelter | 246 | }//end namespace oopse |