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root/OpenMD/branches/development/src/integrators/NPT.cpp
Revision: 1759
Committed: Thu Jun 21 18:55:33 2012 UTC (12 years, 10 months ago) by gezelter
File size: 10975 byte(s)
Log Message:
fixed a directional StuntDouble bug

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, 24107 (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 <math.h>
44
45 #include "brains/SimInfo.hpp"
46 #include "brains/Thermo.hpp"
47 #include "integrators/NPT.hpp"
48 #include "math/SquareMatrix3.hpp"
49 #include "primitives/Molecule.hpp"
50 #include "utils/PhysicalConstants.hpp"
51 #include "utils/simError.h"
52
53 // Basic isotropic thermostating and barostating via the Melchionna
54 // modification of the Hoover algorithm:
55 //
56 // Melchionna, S., Ciccotti, G., and Holian, B. L., 1993,
57 // Molec. Phys., 78, 533.
58 //
59 // and
60 //
61 // Hoover, W. G., 1986, Phys. Rev. A, 34, 2499.
62
63 namespace OpenMD {
64
65 NPT::NPT(SimInfo* info) :
66 VelocityVerletIntegrator(info), chiTolerance(1e-6), etaTolerance(1e-6), maxIterNum_(4) {
67
68 Globals* simParams = info_->getSimParams();
69
70 if (!simParams->getUseIntialExtendedSystemState()) {
71 Snapshot* currSnapshot = info_->getSnapshotManager()->getCurrentSnapshot();
72 currSnapshot->setChi(0.0);
73 currSnapshot->setIntegralOfChiDt(0.0);
74 currSnapshot->setEta(Mat3x3d(0.0));
75 }
76
77 if (!simParams->haveTargetTemp()) {
78 sprintf(painCave.errMsg, "You can't use the NVT integrator without a targetTemp!\n");
79 painCave.isFatal = 1;
80 painCave.severity = OPENMD_ERROR;
81 simError();
82 } else {
83 targetTemp = simParams->getTargetTemp();
84 }
85
86 // We must set tauThermostat
87 if (!simParams->haveTauThermostat()) {
88 sprintf(painCave.errMsg, "If you use the constant temperature\n"
89 "\tintegrator, you must set tauThermostat.\n");
90
91 painCave.severity = OPENMD_ERROR;
92 painCave.isFatal = 1;
93 simError();
94 } else {
95 tauThermostat = simParams->getTauThermostat();
96 }
97
98 if (!simParams->haveTargetPressure()) {
99 sprintf(painCave.errMsg, "NPT error: You can't use the NPT integrator\n"
100 " without a targetPressure!\n");
101
102 painCave.isFatal = 1;
103 simError();
104 } else {
105 targetPressure = simParams->getTargetPressure();
106 }
107
108 if (!simParams->haveTauBarostat()) {
109 sprintf(painCave.errMsg,
110 "If you use the NPT integrator, you must set tauBarostat.\n");
111 painCave.severity = OPENMD_ERROR;
112 painCave.isFatal = 1;
113 simError();
114 } else {
115 tauBarostat = simParams->getTauBarostat();
116 }
117
118 tt2 = tauThermostat * tauThermostat;
119 tb2 = tauBarostat * tauBarostat;
120
121 updateSizes();
122 }
123
124 NPT::~NPT() {
125 }
126
127 void NPT::doUpdateSizes() {
128
129 oldPos.resize(info_->getNIntegrableObjects());
130 oldVel.resize(info_->getNIntegrableObjects());
131 oldJi.resize(info_->getNIntegrableObjects());
132
133 }
134
135 void NPT::moveA() {
136 SimInfo::MoleculeIterator i;
137 Molecule::IntegrableObjectIterator j;
138 Molecule* mol;
139 StuntDouble* integrableObject;
140 Vector3d Tb, ji;
141 RealType mass;
142 Vector3d vel;
143 Vector3d pos;
144 Vector3d frc;
145 Vector3d sc;
146 int index;
147
148 chi= currentSnapshot_->getChi();
149 integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
150 loadEta();
151
152 instaTemp =thermo.getTemperature();
153 press = thermo.getPressureTensor();
154 instaPress = PhysicalConstants::pressureConvert* (press(0, 0) + press(1, 1) + press(2, 2)) / 3.0;
155 instaVol =thermo.getVolume();
156
157 Vector3d COM = info_->getCom();
158
159 //evolve velocity half step
160
161 calcVelScale();
162
163 for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
164 for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
165 integrableObject = mol->nextIntegrableObject(j)) {
166
167 vel = integrableObject->getVel();
168 frc = integrableObject->getFrc();
169
170 mass = integrableObject->getMass();
171
172 getVelScaleA(sc, vel);
173
174 // velocity half step (use chi from previous step here):
175 //vel[j] += dt2 * ((frc[j] / mass) * PhysicalConstants::energyConvert - sc[j]);
176 vel += dt2*PhysicalConstants::energyConvert/mass* frc - dt2*sc;
177 integrableObject->setVel(vel);
178
179 if (integrableObject->isDirectional()) {
180
181 // get and convert the torque to body frame
182
183 Tb = integrableObject->lab2Body(integrableObject->getTrq());
184
185 // get the angular momentum, and propagate a half step
186
187 ji = integrableObject->getJ();
188
189 //ji[j] += dt2 * (Tb[j] * PhysicalConstants::energyConvert - ji[j]*chi);
190 ji += dt2*PhysicalConstants::energyConvert * Tb - dt2*chi* ji;
191
192 rotAlgo_->rotate(integrableObject, ji, dt);
193
194 integrableObject->setJ(ji);
195 }
196
197 }
198 }
199 // evolve chi and eta half step
200
201 chi += dt2 * (instaTemp / targetTemp - 1.0) / tt2;
202
203 evolveEtaA();
204
205 //calculate the integral of chidt
206 integralOfChidt += dt2 * chi;
207
208 flucQ_->moveA();
209
210
211 index = 0;
212 for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
213 for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
214 integrableObject = mol->nextIntegrableObject(j)) {
215 oldPos[index++] = integrableObject->getPos();
216 }
217 }
218
219 //the first estimation of r(t+dt) is equal to r(t)
220
221 for(int k = 0; k < maxIterNum_; k++) {
222 index = 0;
223 for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
224 for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
225 integrableObject = mol->nextIntegrableObject(j)) {
226
227 vel = integrableObject->getVel();
228 pos = integrableObject->getPos();
229
230 this->getPosScale(pos, COM, index, sc);
231
232 pos = oldPos[index] + dt * (vel + sc);
233 integrableObject->setPos(pos);
234
235 ++index;
236 }
237 }
238
239 rattle_->constraintA();
240 }
241
242 // Scale the box after all the positions have been moved:
243
244 this->scaleSimBox();
245
246 currentSnapshot_->setChi(chi);
247 currentSnapshot_->setIntegralOfChiDt(integralOfChidt);
248
249 saveEta();
250 }
251
252 void NPT::moveB(void) {
253 SimInfo::MoleculeIterator i;
254 Molecule::IntegrableObjectIterator j;
255 Molecule* mol;
256 StuntDouble* integrableObject;
257 int index;
258 Vector3d Tb;
259 Vector3d ji;
260 Vector3d sc;
261 Vector3d vel;
262 Vector3d frc;
263 RealType mass;
264
265
266 chi= currentSnapshot_->getChi();
267 integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
268 RealType oldChi = chi;
269 RealType prevChi;
270
271 loadEta();
272
273 //save velocity and angular momentum
274 index = 0;
275 for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
276 for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
277 integrableObject = mol->nextIntegrableObject(j)) {
278
279 oldVel[index] = integrableObject->getVel();
280
281 if (integrableObject->isDirectional())
282 oldJi[index] = integrableObject->getJ();
283
284 ++index;
285 }
286 }
287
288 // do the iteration:
289 instaVol =thermo.getVolume();
290
291 for(int k = 0; k < maxIterNum_; k++) {
292 instaTemp =thermo.getTemperature();
293 instaPress =thermo.getPressure();
294
295 // evolve chi another half step using the temperature at t + dt/2
296 prevChi = chi;
297 chi = oldChi + dt2 * (instaTemp / targetTemp - 1.0) / tt2;
298
299 //evolve eta
300 this->evolveEtaB();
301 this->calcVelScale();
302
303 index = 0;
304 for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
305 for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
306 integrableObject = mol->nextIntegrableObject(j)) {
307
308 frc = integrableObject->getFrc();
309 vel = integrableObject->getVel();
310
311 mass = integrableObject->getMass();
312
313 getVelScaleB(sc, index);
314
315 // velocity half step
316 //vel[j] = oldVel[3 * i + j] + dt2 *((frc[j] / mass) * PhysicalConstants::energyConvert - sc[j]);
317 vel = oldVel[index] + dt2*PhysicalConstants::energyConvert/mass* frc - dt2*sc;
318 integrableObject->setVel(vel);
319
320 if (integrableObject->isDirectional()) {
321 // get and convert the torque to body frame
322 Tb = integrableObject->lab2Body(integrableObject->getTrq());
323
324 //ji[j] = oldJi[3*i + j] + dt2 * (Tb[j] * PhysicalConstants::energyConvert - oldJi[3*i+j]*chi);
325 ji = oldJi[index] + dt2*PhysicalConstants::energyConvert*Tb - dt2*chi*oldJi[index];
326 integrableObject->setJ(ji);
327 }
328
329 ++index;
330 }
331 }
332
333 rattle_->constraintB();
334
335 if ((fabs(prevChi - chi) <= chiTolerance) && this->etaConverged())
336 break;
337 }
338
339 //calculate integral of chidt
340 integralOfChidt += dt2 * chi;
341
342 currentSnapshot_->setChi(chi);
343 currentSnapshot_->setIntegralOfChiDt(integralOfChidt);
344
345 flucQ_->moveB();
346 saveEta();
347 }
348
349 void NPT::resetIntegrator(){
350 currentSnapshot_->setChi(0.0);
351 currentSnapshot_->setIntegralOfChiDt(0.0);
352 resetEta();
353 }
354
355
356 void NPT::resetEta() {
357 Mat3x3d etaMat(0.0);
358 currentSnapshot_->setEta(etaMat);
359 }
360
361 }

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