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root/OpenMD/trunk/src/constraints/Shake.cpp
Revision: 1982
Committed: Tue Apr 15 12:12:23 2014 UTC (11 years ago) by gezelter
File size: 9391 byte(s)
Log Message:
Migrated ConstraintWriter calls into Shake

File Contents

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

Properties

Name Value
svn:eol-style native
svn:executable *