| 1 | gezelter | 1748 | /* | 
| 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 | gezelter | 1879 | * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008). | 
| 39 | gezelter | 1748 | * [4]  Kuang & Gezelter,  J. Chem. Phys. 133, 164101 (2010). | 
| 40 |  |  | * [5]  Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011). | 
| 41 |  |  | */ | 
| 42 |  |  |  | 
| 43 |  |  | #include "constraints/Shake.hpp" | 
| 44 |  |  | #include "primitives/Molecule.hpp" | 
| 45 |  |  | #include "utils/simError.h" | 
| 46 |  |  | namespace OpenMD { | 
| 47 |  |  |  | 
| 48 | gezelter | 1983 | Shake::Shake(SimInfo* info) : info_(info), maxConsIteration_(10), | 
| 49 |  |  | consTolerance_(1.0e-6), doShake_(false), | 
| 50 |  |  | currConstraintTime_(0.0)  { | 
| 51 | gezelter | 1748 |  | 
| 52 | gezelter | 1982 | if (info_->getNGlobalConstraints() > 0) | 
| 53 | gezelter | 1748 | doShake_ = true; | 
| 54 |  |  |  | 
| 55 | gezelter | 1982 | Globals* simParams = info_->getSimParams(); | 
| 56 |  |  |  | 
| 57 | gezelter | 1748 | currentSnapshot_ = info_->getSnapshotManager()->getCurrentSnapshot(); | 
| 58 | gezelter | 1982 | if (simParams->haveConstraintTime()){ | 
| 59 |  |  | constraintTime_ = simParams->getConstraintTime(); | 
| 60 |  |  | } else { | 
| 61 |  |  | constraintTime_ = simParams->getStatusTime(); | 
| 62 |  |  | } | 
| 63 |  |  |  | 
| 64 | gezelter | 1983 | constraintOutputFile_ = getPrefix(info_->getFinalConfigFileName()) + | 
| 65 |  |  | ".constraintForces"; | 
| 66 | gezelter | 1982 |  | 
| 67 |  |  | // create ConstraintWriter | 
| 68 | gezelter | 1983 | constraintWriter_ = new ConstraintWriter(info_, | 
| 69 |  |  | constraintOutputFile_.c_str()); | 
| 70 | gezelter | 1982 |  | 
| 71 |  |  | if (!constraintWriter_){ | 
| 72 |  |  | sprintf(painCave.errMsg, "Failed to create ConstraintWriter\n"); | 
| 73 |  |  | painCave.isFatal = 1; | 
| 74 |  |  | simError(); | 
| 75 |  |  | } | 
| 76 | gezelter | 1748 | } | 
| 77 |  |  |  | 
| 78 |  |  | void Shake::constraintR() { | 
| 79 |  |  | if (!doShake_) return; | 
| 80 |  |  | doConstraint(&Shake::constraintPairR); | 
| 81 |  |  | } | 
| 82 |  |  | void Shake::constraintF() { | 
| 83 |  |  | if (!doShake_) return; | 
| 84 |  |  | doConstraint(&Shake::constraintPairF); | 
| 85 | gezelter | 1982 |  | 
| 86 |  |  | if (currentSnapshot_->getTime() >= currConstraintTime_){ | 
| 87 |  |  | Molecule* mol; | 
| 88 |  |  | SimInfo::MoleculeIterator mi; | 
| 89 |  |  | ConstraintPair* consPair; | 
| 90 |  |  | Molecule::ConstraintPairIterator cpi; | 
| 91 |  |  | std::list<ConstraintPair*> constraints; | 
| 92 |  |  | for (mol = info_->beginMolecule(mi); mol != NULL; | 
| 93 |  |  | mol = info_->nextMolecule(mi)) { | 
| 94 |  |  | for (consPair = mol->beginConstraintPair(cpi); consPair != NULL; | 
| 95 |  |  | consPair = mol->nextConstraintPair(cpi)) { | 
| 96 |  |  |  | 
| 97 |  |  | constraints.push_back(consPair); | 
| 98 |  |  | } | 
| 99 |  |  | } | 
| 100 |  |  |  | 
| 101 |  |  | constraintWriter_->writeConstraintForces(constraints); | 
| 102 |  |  | currConstraintTime_ += constraintTime_; | 
| 103 |  |  | } | 
| 104 | gezelter | 1748 | } | 
| 105 |  |  |  | 
| 106 |  |  | void Shake::doConstraint(ConstraintPairFuncPtr func) { | 
| 107 |  |  | if (!doShake_) return; | 
| 108 |  |  |  | 
| 109 |  |  | Molecule* mol; | 
| 110 |  |  | SimInfo::MoleculeIterator mi; | 
| 111 |  |  | ConstraintElem* consElem; | 
| 112 |  |  | Molecule::ConstraintElemIterator cei; | 
| 113 |  |  | ConstraintPair* consPair; | 
| 114 |  |  | Molecule::ConstraintPairIterator cpi; | 
| 115 |  |  |  | 
| 116 | gezelter | 1982 | for (mol = info_->beginMolecule(mi); mol != NULL; | 
| 117 |  |  | mol = info_->nextMolecule(mi)) { | 
| 118 |  |  | for (consElem = mol->beginConstraintElem(cei); consElem != NULL; | 
| 119 |  |  | consElem = mol->nextConstraintElem(cei)) { | 
| 120 | gezelter | 1748 | consElem->setMoved(true); | 
| 121 |  |  | consElem->setMoving(false); | 
| 122 |  |  | } | 
| 123 |  |  | } | 
| 124 |  |  |  | 
| 125 |  |  | //main loop of constraint algorithm | 
| 126 |  |  | bool done = false; | 
| 127 |  |  | int iteration = 0; | 
| 128 |  |  | while(!done && iteration < maxConsIteration_){ | 
| 129 |  |  | done = true; | 
| 130 |  |  |  | 
| 131 |  |  | //loop over every constraint pair | 
| 132 |  |  |  | 
| 133 | gezelter | 1982 | for (mol = info_->beginMolecule(mi); mol != NULL; | 
| 134 |  |  | mol = info_->nextMolecule(mi)) { | 
| 135 |  |  | for (consPair = mol->beginConstraintPair(cpi); consPair != NULL; | 
| 136 |  |  | consPair = mol->nextConstraintPair(cpi)) { | 
| 137 |  |  |  | 
| 138 | gezelter | 1748 |  | 
| 139 |  |  | //dispatch constraint algorithm | 
| 140 |  |  | if(consPair->isMoved()) { | 
| 141 |  |  | int exeStatus = (this->*func)(consPair); | 
| 142 |  |  |  | 
| 143 |  |  | switch(exeStatus){ | 
| 144 |  |  | case consFail: | 
| 145 |  |  | sprintf(painCave.errMsg, | 
| 146 | gezelter | 1982 | "Constraint failure in Shake::constrainA, " | 
| 147 |  |  | "Constraint Fail\n"); | 
| 148 | gezelter | 1748 | painCave.isFatal = 1; | 
| 149 |  |  | simError(); | 
| 150 |  |  |  | 
| 151 |  |  | break; | 
| 152 |  |  | case consSuccess: | 
| 153 | gezelter | 1982 | // constrain the pair by moving two elements | 
| 154 | gezelter | 1748 | done = false; | 
| 155 |  |  | consPair->getConsElem1()->setMoving(true); | 
| 156 |  |  | consPair->getConsElem2()->setMoving(true); | 
| 157 |  |  | break; | 
| 158 |  |  | case consAlready: | 
| 159 | gezelter | 1982 | // current pair is already constrained, do not need to | 
| 160 |  |  | // move the elements | 
| 161 | gezelter | 1748 | break; | 
| 162 |  |  | default: | 
| 163 | gezelter | 1982 | sprintf(painCave.errMsg, "ConstraintAlgorithm::doConstraint() " | 
| 164 |  |  | "Error: unrecognized status"); | 
| 165 | gezelter | 1748 | painCave.isFatal = 1; | 
| 166 |  |  | simError(); | 
| 167 |  |  | break; | 
| 168 |  |  | } | 
| 169 |  |  | } | 
| 170 |  |  | } | 
| 171 |  |  | }//end for(iter->first()) | 
| 172 |  |  |  | 
| 173 |  |  |  | 
| 174 | gezelter | 1982 | for (mol = info_->beginMolecule(mi); mol != NULL; | 
| 175 |  |  | mol = info_->nextMolecule(mi)) { | 
| 176 |  |  | for (consElem = mol->beginConstraintElem(cei); consElem != NULL; | 
| 177 |  |  | consElem = mol->nextConstraintElem(cei)) { | 
| 178 | gezelter | 1748 | consElem->setMoved(consElem->getMoving()); | 
| 179 |  |  | consElem->setMoving(false); | 
| 180 |  |  | } | 
| 181 |  |  | } | 
| 182 |  |  |  | 
| 183 |  |  | iteration++; | 
| 184 |  |  | }//end while | 
| 185 |  |  |  | 
| 186 |  |  | if (!done){ | 
| 187 |  |  | sprintf(painCave.errMsg, | 
| 188 | gezelter | 1982 | "Constraint failure in Shake::constrainA, " | 
| 189 |  |  | "too many iterations: %d\n", | 
| 190 | gezelter | 1748 | iteration); | 
| 191 |  |  | painCave.isFatal = 1; | 
| 192 |  |  | simError(); | 
| 193 |  |  | } | 
| 194 |  |  | } | 
| 195 |  |  |  | 
| 196 |  |  | /** | 
| 197 |  |  | * remove constraint force along the bond direction | 
| 198 |  |  | */ | 
| 199 |  |  | int Shake::constraintPairR(ConstraintPair* consPair){ | 
| 200 |  |  |  | 
| 201 |  |  | ConstraintElem* consElem1 = consPair->getConsElem1(); | 
| 202 |  |  | ConstraintElem* consElem2 = consPair->getConsElem2(); | 
| 203 |  |  |  | 
| 204 |  |  | Vector3d posA = consElem1->getPos(); | 
| 205 |  |  | Vector3d posB = consElem2->getPos(); | 
| 206 |  |  |  | 
| 207 |  |  | Vector3d pab = posA -posB; | 
| 208 |  |  |  | 
| 209 |  |  | //periodic boundary condition | 
| 210 |  |  |  | 
| 211 |  |  | currentSnapshot_->wrapVector(pab); | 
| 212 |  |  |  | 
| 213 |  |  | RealType pabsq = pab.lengthSquare(); | 
| 214 |  |  |  | 
| 215 |  |  | RealType rabsq = consPair->getConsDistSquare(); | 
| 216 |  |  | RealType diffsq = rabsq - pabsq; | 
| 217 |  |  |  | 
| 218 |  |  | // the original rattle code from alan tidesley | 
| 219 |  |  | if (fabs(diffsq) > (consTolerance_ * rabsq * 2)){ | 
| 220 |  |  |  | 
| 221 |  |  | Vector3d oldPosA = consElem1->getPrevPos(); | 
| 222 |  |  | Vector3d oldPosB = consElem2->getPrevPos(); | 
| 223 |  |  |  | 
| 224 |  |  | Vector3d rab = oldPosA - oldPosB; | 
| 225 |  |  |  | 
| 226 |  |  | currentSnapshot_->wrapVector(rab); | 
| 227 |  |  |  | 
| 228 |  |  | RealType rpab = dot(rab, pab); | 
| 229 |  |  | RealType rpabsq = rpab * rpab; | 
| 230 |  |  |  | 
| 231 |  |  | if (rpabsq < (rabsq * -diffsq)){ | 
| 232 |  |  | return consFail; | 
| 233 |  |  | } | 
| 234 |  |  |  | 
| 235 |  |  | RealType rma = 1.0 / consElem1->getMass(); | 
| 236 |  |  | RealType rmb = 1.0 / consElem2->getMass(); | 
| 237 |  |  |  | 
| 238 |  |  | RealType gab = diffsq / (2.0 * (rma + rmb) * rpab); | 
| 239 |  |  |  | 
| 240 |  |  | Vector3d delta = rab * gab; | 
| 241 |  |  |  | 
| 242 |  |  | //set atom1's position | 
| 243 |  |  | posA += rma * delta; | 
| 244 |  |  | consElem1->setPos(posA); | 
| 245 |  |  |  | 
| 246 |  |  | //set atom2's position | 
| 247 |  |  | posB -= rmb * delta; | 
| 248 |  |  | consElem2->setPos(posB); | 
| 249 | gezelter | 1982 |  | 
| 250 |  |  | // report the constraint force back to the constraint pair: | 
| 251 |  |  | consPair->setConstraintForce(gab); | 
| 252 | gezelter | 1748 | return consSuccess; | 
| 253 |  |  | } | 
| 254 |  |  | else | 
| 255 |  |  | return consAlready; | 
| 256 |  |  | } | 
| 257 |  |  |  | 
| 258 |  |  | /** | 
| 259 |  |  | * remove constraint force along the bond direction | 
| 260 |  |  | */ | 
| 261 |  |  | int Shake::constraintPairF(ConstraintPair* consPair){ | 
| 262 |  |  | ConstraintElem* consElem1 = consPair->getConsElem1(); | 
| 263 |  |  | ConstraintElem* consElem2 = consPair->getConsElem2(); | 
| 264 |  |  |  | 
| 265 |  |  | Vector3d posA = consElem1->getPos(); | 
| 266 |  |  | Vector3d posB = consElem2->getPos(); | 
| 267 |  |  |  | 
| 268 |  |  | Vector3d rab = posA - posB; | 
| 269 |  |  |  | 
| 270 |  |  | currentSnapshot_->wrapVector(rab); | 
| 271 |  |  |  | 
| 272 |  |  | Vector3d frcA = consElem1->getFrc(); | 
| 273 |  |  | Vector3d frcB = consElem2->getFrc(); | 
| 274 |  |  |  | 
| 275 |  |  | RealType rma = 1.0 / consElem1->getMass(); | 
| 276 |  |  | RealType rmb = 1.0 / consElem2->getMass(); | 
| 277 |  |  |  | 
| 278 |  |  | Vector3d fpab = frcA * rma - frcB * rmb; | 
| 279 |  |  |  | 
| 280 |  |  | RealType gab = fpab.lengthSquare(); | 
| 281 |  |  | if (gab < 1.0) gab = 1.0; | 
| 282 |  |  |  | 
| 283 |  |  | RealType rabsq = rab.lengthSquare(); | 
| 284 |  |  | RealType rfab = dot(rab, fpab); | 
| 285 |  |  |  | 
| 286 |  |  | if (fabs(rfab) > sqrt(rabsq*gab) * consTolerance_){ | 
| 287 |  |  | gab = -rfab / (rabsq * (rma + rmb)); | 
| 288 |  |  |  | 
| 289 |  |  | frcA += rab*gab; | 
| 290 |  |  | frcB -= rab*gab; | 
| 291 |  |  |  | 
| 292 |  |  | consElem1->setFrc(frcA); | 
| 293 |  |  | consElem2->setFrc(frcB); | 
| 294 |  |  |  | 
| 295 | gezelter | 1982 | // report the constraint force back to the constraint pair: | 
| 296 |  |  | consPair->setConstraintForce(gab); | 
| 297 | gezelter | 1748 | return consSuccess; | 
| 298 |  |  | } | 
| 299 |  |  | else | 
| 300 |  |  | return consAlready; | 
| 301 |  |  | } | 
| 302 |  |  | } |