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root/group/trunk/OOPSE/libmdtools/NPT.cpp
Revision: 837
Committed: Wed Oct 29 00:19:10 2003 UTC (20 years, 8 months ago) by tim
File size: 8200 byte(s)
Log Message:
add chi and eta to the comment line of dump file.

File Contents

# Content
1 #include <math.h>
2 #include "Atom.hpp"
3 #include "SRI.hpp"
4 #include "AbstractClasses.hpp"
5 #include "SimInfo.hpp"
6 #include "ForceFields.hpp"
7 #include "Thermo.hpp"
8 #include "ReadWrite.hpp"
9 #include "Integrator.hpp"
10 #include "simError.h"
11
12 #ifdef IS_MPI
13 #include "mpiSimulation.hpp"
14 #endif
15
16
17 // Basic isotropic thermostating and barostating via the Melchionna
18 // modification of the Hoover algorithm:
19 //
20 // Melchionna, S., Ciccotti, G., and Holian, B. L., 1993,
21 // Molec. Phys., 78, 533.
22 //
23 // and
24 //
25 // Hoover, W. G., 1986, Phys. Rev. A, 34, 2499.
26
27 template<typename T> NPT<T>::NPT ( SimInfo *theInfo, ForceFields* the_ff):
28 T( theInfo, the_ff )
29 {
30 GenericData* data;
31 DoubleData * chiValue;
32 DoubleData * integralOfChidtValue;
33
34 chiValue = NULL;
35 integralOfChidtValue = NULL;
36
37 chi = 0.0;
38 integralOfChidt = 0.0;
39 have_tau_thermostat = 0;
40 have_tau_barostat = 0;
41 have_target_temp = 0;
42 have_target_pressure = 0;
43 have_chi_tolerance = 0;
44 have_eta_tolerance = 0;
45 have_pos_iter_tolerance = 0;
46
47 // retrieve chi and integralOfChidt from simInfo
48 data = info->getProperty(CHIVALUE_ID);
49 if(data){
50 chiValue = dynamic_cast<DoubleData*>(data);
51 }
52
53 data = info->getProperty(INTEGRALOFCHIDT_ID);
54 if(data){
55 integralOfChidtValue = dynamic_cast<DoubleData*>(data);
56 }
57
58 // chi and integralOfChidt should appear by pair
59 if(chiValue && integralOfChidtValue){
60 chi = chiValue->getData();
61 integralOfChidt = integralOfChidtValue->getData();
62 }
63
64 oldPos = new double[3*nAtoms];
65 oldVel = new double[3*nAtoms];
66 oldJi = new double[3*nAtoms];
67 #ifdef IS_MPI
68 Nparticles = mpiSim->getTotAtoms();
69 #else
70 Nparticles = theInfo->n_atoms;
71 #endif
72
73 }
74
75 template<typename T> NPT<T>::~NPT() {
76 delete[] oldPos;
77 delete[] oldVel;
78 delete[] oldJi;
79 }
80
81 template<typename T> void NPT<T>::moveA() {
82
83 //new version of NPT
84 int i, j, k;
85 DirectionalAtom* dAtom;
86 double Tb[3], ji[3];
87 double mass;
88 double vel[3], pos[3], frc[3];
89 double sc[3];
90 double COM[3];
91
92 instaTemp = tStats->getTemperature();
93 tStats->getPressureTensor( press );
94 instaPress = p_convert * (press[0][0] + press[1][1] + press[2][2]) / 3.0;
95 instaVol = tStats->getVolume();
96
97 tStats->getCOM(COM);
98
99 //evolve velocity half step
100 for( i=0; i<nAtoms; i++ ){
101
102 atoms[i]->getVel( vel );
103 atoms[i]->getFrc( frc );
104
105 mass = atoms[i]->getMass();
106
107 getVelScaleA( sc, vel );
108
109 for (j=0; j < 3; j++) {
110
111 // velocity half step (use chi from previous step here):
112 vel[j] += dt2 * ((frc[j] / mass ) * eConvert - sc[j]);
113
114 }
115
116 atoms[i]->setVel( vel );
117
118 if( atoms[i]->isDirectional() ){
119
120 dAtom = (DirectionalAtom *)atoms[i];
121
122 // get and convert the torque to body frame
123
124 dAtom->getTrq( Tb );
125 dAtom->lab2Body( Tb );
126
127 // get the angular momentum, and propagate a half step
128
129 dAtom->getJ( ji );
130
131 for (j=0; j < 3; j++)
132 ji[j] += dt2 * (Tb[j] * eConvert - ji[j]*chi);
133
134 this->rotationPropagation( dAtom, ji );
135
136 dAtom->setJ( ji );
137 }
138 }
139
140 // evolve chi and eta half step
141
142 evolveChiA();
143 evolveEtaA();
144
145 //calculate the integral of chidt
146 integralOfChidt += dt2*chi;
147
148 //save the old positions
149 for(i = 0; i < nAtoms; i++){
150 atoms[i]->getPos(pos);
151 for(j = 0; j < 3; j++)
152 oldPos[i*3 + j] = pos[j];
153 }
154
155 //the first estimation of r(t+dt) is equal to r(t)
156
157 for(k = 0; k < 5; k ++){
158
159 for(i =0 ; i < nAtoms; i++){
160
161 atoms[i]->getVel(vel);
162 atoms[i]->getPos(pos);
163
164 this->getPosScale( pos, COM, i, sc );
165
166 for(j = 0; j < 3; j++)
167 pos[j] = oldPos[i*3 + j] + dt*(vel[j] + sc[j]);
168
169 atoms[i]->setPos( pos );
170 }
171
172 if (nConstrained){
173 constrainA();
174 }
175 }
176
177
178 // Scale the box after all the positions have been moved:
179
180 this->scaleSimBox();
181 }
182
183 template<typename T> void NPT<T>::moveB( void ){
184
185 //new version of NPT
186 int i, j, k;
187 DirectionalAtom* dAtom;
188 double Tb[3], ji[3], sc[3];
189 double vel[3], frc[3];
190 double mass;
191
192 // Set things up for the iteration:
193
194 for( i=0; i<nAtoms; i++ ){
195
196 atoms[i]->getVel( vel );
197
198 for (j=0; j < 3; j++)
199 oldVel[3*i + j] = vel[j];
200
201 if( atoms[i]->isDirectional() ){
202
203 dAtom = (DirectionalAtom *)atoms[i];
204
205 dAtom->getJ( ji );
206
207 for (j=0; j < 3; j++)
208 oldJi[3*i + j] = ji[j];
209
210 }
211 }
212
213 // do the iteration:
214
215 instaVol = tStats->getVolume();
216
217 for (k=0; k < 4; k++) {
218
219 instaTemp = tStats->getTemperature();
220 instaPress = tStats->getPressure();
221
222 // evolve chi another half step using the temperature at t + dt/2
223
224 this->evolveChiB();
225 this->evolveEtaB();
226
227 for( i=0; i<nAtoms; i++ ){
228
229 atoms[i]->getFrc( frc );
230 atoms[i]->getVel(vel);
231
232 mass = atoms[i]->getMass();
233
234 getVelScaleB( sc, i );
235
236 // velocity half step
237 for (j=0; j < 3; j++)
238 vel[j] = oldVel[3*i+j] + dt2 * ((frc[j] / mass ) * eConvert - sc[j]);
239
240 atoms[i]->setVel( vel );
241
242 if( atoms[i]->isDirectional() ){
243
244 dAtom = (DirectionalAtom *)atoms[i];
245
246 // get and convert the torque to body frame
247
248 dAtom->getTrq( Tb );
249 dAtom->lab2Body( Tb );
250
251 for (j=0; j < 3; j++)
252 ji[j] = oldJi[3*i + j] + dt2 * (Tb[j] * eConvert - oldJi[3*i+j]*chi);
253
254 dAtom->setJ( ji );
255 }
256 }
257
258 if (nConstrained){
259 constrainB();
260 }
261
262 if ( this->chiConverged() && this->etaConverged() ) break;
263 }
264
265 //calculate integral of chida
266 integralOfChidt += dt2*chi;
267
268
269 }
270
271 template<typename T> void NPT<T>::resetIntegrator() {
272 chi = 0.0;
273 T::resetIntegrator();
274 }
275
276 template<typename T> void NPT<T>::evolveChiA() {
277 chi += dt2 * ( instaTemp / targetTemp - 1.0) / tt2;
278 oldChi = chi;
279 }
280
281 template<typename T> void NPT<T>::evolveChiB() {
282
283 prevChi = chi;
284 chi = oldChi + dt2 * ( instaTemp / targetTemp - 1.0) / tt2;
285 }
286
287 template<typename T> bool NPT<T>::chiConverged() {
288
289 return ( fabs( prevChi - chi ) <= chiTolerance );
290 }
291
292 template<typename T> int NPT<T>::readyCheck() {
293
294 //check parent's readyCheck() first
295 if (T::readyCheck() == -1)
296 return -1;
297
298 // First check to see if we have a target temperature.
299 // Not having one is fatal.
300
301 if (!have_target_temp) {
302 sprintf( painCave.errMsg,
303 "NPT error: You can't use the NPT integrator\n"
304 " without a targetTemp!\n"
305 );
306 painCave.isFatal = 1;
307 simError();
308 return -1;
309 }
310
311 if (!have_target_pressure) {
312 sprintf( painCave.errMsg,
313 "NPT error: You can't use the NPT integrator\n"
314 " without a targetPressure!\n"
315 );
316 painCave.isFatal = 1;
317 simError();
318 return -1;
319 }
320
321 // We must set tauThermostat.
322
323 if (!have_tau_thermostat) {
324 sprintf( painCave.errMsg,
325 "NPT error: If you use the NPT\n"
326 " integrator, you must set tauThermostat.\n");
327 painCave.isFatal = 1;
328 simError();
329 return -1;
330 }
331
332 // We must set tauBarostat.
333
334 if (!have_tau_barostat) {
335 sprintf( painCave.errMsg,
336 "NPT error: If you use the NPT\n"
337 " integrator, you must set tauBarostat.\n");
338 painCave.isFatal = 1;
339 simError();
340 return -1;
341 }
342
343 if (!have_chi_tolerance) {
344 sprintf( painCave.errMsg,
345 "NPT warning: setting chi tolerance to 1e-6\n");
346 chiTolerance = 1e-6;
347 have_chi_tolerance = 1;
348 painCave.isFatal = 0;
349 simError();
350 }
351
352 if (!have_eta_tolerance) {
353 sprintf( painCave.errMsg,
354 "NPT warning: setting eta tolerance to 1e-6\n");
355 etaTolerance = 1e-6;
356 have_eta_tolerance = 1;
357 painCave.isFatal = 0;
358 simError();
359 }
360
361 // We need NkBT a lot, so just set it here: This is the RAW number
362 // of particles, so no subtraction or addition of constraints or
363 // orientational degrees of freedom:
364
365 NkBT = (double)Nparticles * kB * targetTemp;
366
367 // fkBT is used because the thermostat operates on more degrees of freedom
368 // than the barostat (when there are particles with orientational degrees
369 // of freedom). ndf = 3 * (n_atoms + n_oriented -1) - n_constraint - nZcons
370
371 fkBT = (double)info->ndf * kB * targetTemp;
372
373 tt2 = tauThermostat * tauThermostat;
374 tb2 = tauBarostat * tauBarostat;
375
376 return 1;
377 }