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root/group/trunk/OOPSE/libmdtools/Thermo.cpp
Revision: 1131
Committed: Thu Apr 22 21:33:55 2004 UTC (20 years, 2 months ago) by tim
File size: 10251 byte(s)
Log Message:
change the calculation of pressure tensor

File Contents

# Content
1 #include <math.h>
2 #include <iostream>
3 using namespace std;
4
5 #ifdef IS_MPI
6 #include <mpi.h>
7 #endif //is_mpi
8
9 #include "Thermo.hpp"
10 #include "SRI.hpp"
11 #include "Integrator.hpp"
12 #include "simError.h"
13 #include "MatVec3.h"
14
15 #ifdef IS_MPI
16 #define __C
17 #include "mpiSimulation.hpp"
18 #endif // is_mpi
19
20 Thermo::Thermo( SimInfo* the_info ) {
21 info = the_info;
22 int baseSeed = the_info->getSeed();
23
24 gaussStream = new gaussianSPRNG( baseSeed );
25 }
26
27 Thermo::~Thermo(){
28 delete gaussStream;
29 }
30
31 double Thermo::getKinetic(){
32
33 const double e_convert = 4.184E-4; // convert kcal/mol -> (amu A^2)/fs^2
34 double kinetic;
35 double amass;
36 double aVel[3], aJ[3], I[3][3];
37 int i, j, k, kl;
38
39 double kinetic_global;
40 vector<StuntDouble *> integrableObjects = info->integrableObjects;
41
42 kinetic = 0.0;
43 kinetic_global = 0.0;
44
45 for (kl=0; kl<integrableObjects.size(); kl++) {
46 integrableObjects[kl]->getVel(aVel);
47 amass = integrableObjects[kl]->getMass();
48
49 for(j=0; j<3; j++)
50 kinetic += amass*aVel[j]*aVel[j];
51
52 if (integrableObjects[kl]->isDirectional()){
53
54 integrableObjects[kl]->getJ( aJ );
55 integrableObjects[kl]->getI( I );
56
57 if (integrableObjects[kl]->isLinear()) {
58 i = integrableObjects[kl]->linearAxis();
59 j = (i+1)%3;
60 k = (i+2)%3;
61 kinetic += aJ[j]*aJ[j]/I[j][j] + aJ[k]*aJ[k]/I[k][k];
62 } else {
63 for (j=0; j<3; j++)
64 kinetic += aJ[j]*aJ[j] / I[j][j];
65 }
66 }
67 }
68 #ifdef IS_MPI
69 MPI_Allreduce(&kinetic,&kinetic_global,1,MPI_DOUBLE,
70 MPI_SUM, MPI_COMM_WORLD);
71 kinetic = kinetic_global;
72 #endif //is_mpi
73
74 kinetic = kinetic * 0.5 / e_convert;
75
76 return kinetic;
77 }
78
79 double Thermo::getPotential(){
80
81 double potential_local;
82 double potential;
83 int el, nSRI;
84 Molecule* molecules;
85
86 molecules = info->molecules;
87 nSRI = info->n_SRI;
88
89 potential_local = 0.0;
90 potential = 0.0;
91 potential_local += info->lrPot;
92
93 for( el=0; el<info->n_mol; el++ ){
94 potential_local += molecules[el].getPotential();
95 }
96
97 // Get total potential for entire system from MPI.
98 #ifdef IS_MPI
99 MPI_Allreduce(&potential_local,&potential,1,MPI_DOUBLE,
100 MPI_SUM, MPI_COMM_WORLD);
101 #else
102 potential = potential_local;
103 #endif // is_mpi
104
105 return potential;
106 }
107
108 double Thermo::getTotalE(){
109
110 double total;
111
112 total = this->getKinetic() + this->getPotential();
113 return total;
114 }
115
116 double Thermo::getTemperature(){
117
118 const double kb = 1.9872156E-3; // boltzman's constant in kcal/(mol K)
119 double temperature;
120
121 temperature = ( 2.0 * this->getKinetic() ) / ((double)info->ndf * kb );
122 return temperature;
123 }
124
125 double Thermo::getVolume() {
126
127 return info->boxVol;
128 }
129
130 double Thermo::getPressure() {
131
132 // Relies on the calculation of the full molecular pressure tensor
133
134 const double p_convert = 1.63882576e8;
135 double press[3][3];
136 double pressure;
137
138 this->getPressureTensor(press);
139
140 pressure = p_convert * (press[0][0] + press[1][1] + press[2][2]) / 3.0;
141
142 return pressure;
143 }
144
145 double Thermo::getPressureX() {
146
147 // Relies on the calculation of the full molecular pressure tensor
148
149 const double p_convert = 1.63882576e8;
150 double press[3][3];
151 double pressureX;
152
153 this->getPressureTensor(press);
154
155 pressureX = p_convert * press[0][0];
156
157 return pressureX;
158 }
159
160 double Thermo::getPressureY() {
161
162 // Relies on the calculation of the full molecular pressure tensor
163
164 const double p_convert = 1.63882576e8;
165 double press[3][3];
166 double pressureY;
167
168 this->getPressureTensor(press);
169
170 pressureY = p_convert * press[1][1];
171
172 return pressureY;
173 }
174
175 double Thermo::getPressureZ() {
176
177 // Relies on the calculation of the full molecular pressure tensor
178
179 const double p_convert = 1.63882576e8;
180 double press[3][3];
181 double pressureZ;
182
183 this->getPressureTensor(press);
184
185 pressureZ = p_convert * press[2][2];
186
187 return pressureZ;
188 }
189
190
191 void Thermo::getPressureTensor(double press[3][3]){
192 // returns pressure tensor in units amu*fs^-2*Ang^-1
193 // routine derived via viral theorem description in:
194 // Paci, E. and Marchi, M. J.Phys.Chem. 1996, 100, 4314-4322
195
196 const double e_convert = 4.184e-4;
197
198 double molmass, volume;
199 double vcom[3], pcom[3], fcom[3], scaled[3];
200 double p_local[9], p_global[9];
201 int i, j, k, nMols;
202 Molecule* molecules;
203
204 nMols = info->n_mol;
205 molecules = info->molecules;
206 //tau = info->tau;
207
208 // use velocities of molecular centers of mass and molecular masses:
209 for (i=0; i < 9; i++) {
210 p_local[i] = 0.0;
211 p_global[i] = 0.0;
212 }
213
214 for (i=0; i < info->integrableObjects.size(); i++) {
215
216 molmass = info->integrableObjects[i]->getMass();
217
218 info->integrableObjects[i]->getVel(vcom);
219 info->integrableObjects[i]->getPos(pcom);
220 info->integrableObjects[i]->getFrc(fcom);
221
222 matVecMul3(info->HmatInv, pcom, scaled);
223
224 for(j=0; j<3; j++)
225 scaled[j] -= roundMe(scaled[j]);
226
227 // calc the wrapped real coordinates from the wrapped scaled coordinates
228
229 matVecMul3(info->Hmat, scaled, pcom);
230
231 p_local[0] += molmass * (vcom[0] * vcom[0]) + fcom[0]*pcom[0]*eConvert;
232 p_local[1] += molmass * (vcom[0] * vcom[1]) + fcom[0]*pcom[1]*eConvert;
233 p_local[2] += molmass * (vcom[0] * vcom[2]) + fcom[0]*pcom[2]*eConvert;
234 p_local[3] += molmass * (vcom[1] * vcom[0]) + fcom[1]*pcom[0]*eConvert;
235 p_local[4] += molmass * (vcom[1] * vcom[1]) + fcom[1]*pcom[1]*eConvert;
236 p_local[5] += molmass * (vcom[1] * vcom[2]) + fcom[1]*pcom[2]*eConvert;
237 p_local[6] += molmass * (vcom[2] * vcom[0]) + fcom[2]*pcom[0]*eConvert;
238 p_local[7] += molmass * (vcom[2] * vcom[1]) + fcom[2]*pcom[1]*eConvert;
239 p_local[8] += molmass * (vcom[2] * vcom[2]) + fcom[2]*pcom[2]*eConvert;
240
241 }
242
243 // Get total for entire system from MPI.
244
245 #ifdef IS_MPI
246 MPI_Allreduce(p_local,p_global,9,MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
247 #else
248 for (i=0; i<9; i++) {
249 p_global[i] = p_local[i];
250 }
251 #endif // is_mpi
252
253 volume = this->getVolume();
254
255 for(i = 0; i < 3; i++) {
256 for (j = 0; j < 3; j++) {
257 k = 3*i + j;
258 press[i][j] = p_global[k] / volume;
259
260 }
261 }
262 }
263
264 void Thermo::velocitize() {
265
266 double aVel[3], aJ[3], I[3][3];
267 int i, j, l, m, n, vr, vd; // velocity randomizer loop counters
268 double vdrift[3];
269 double vbar;
270 const double kb = 8.31451e-7; // kb in amu, angstroms, fs, etc.
271 double av2;
272 double kebar;
273 double temperature;
274 int nobj;
275
276 nobj = info->integrableObjects.size();
277
278 temperature = info->target_temp;
279
280 kebar = kb * temperature * (double)info->ndfRaw /
281 ( 2.0 * (double)info->ndf );
282
283 for(vr = 0; vr < nobj; vr++){
284
285 // uses equipartition theory to solve for vbar in angstrom/fs
286
287 av2 = 2.0 * kebar / info->integrableObjects[vr]->getMass();
288 vbar = sqrt( av2 );
289
290 // picks random velocities from a gaussian distribution
291 // centered on vbar
292
293 for (j=0; j<3; j++)
294 aVel[j] = vbar * gaussStream->getGaussian();
295
296 info->integrableObjects[vr]->setVel( aVel );
297
298 if(info->integrableObjects[vr]->isDirectional()){
299
300 info->integrableObjects[vr]->getI( I );
301
302 if (info->integrableObjects[vr]->isLinear()) {
303
304 l= info->integrableObjects[vr]->linearAxis();
305 m = (l+1)%3;
306 n = (l+2)%3;
307
308 aJ[l] = 0.0;
309 vbar = sqrt( 2.0 * kebar * I[m][m] );
310 aJ[m] = vbar * gaussStream->getGaussian();
311 vbar = sqrt( 2.0 * kebar * I[n][n] );
312 aJ[n] = vbar * gaussStream->getGaussian();
313
314 } else {
315 for (j = 0 ; j < 3; j++) {
316 vbar = sqrt( 2.0 * kebar * I[j][j] );
317 aJ[j] = vbar * gaussStream->getGaussian();
318 }
319 } // else isLinear
320
321 info->integrableObjects[vr]->setJ( aJ );
322
323 }//isDirectional
324
325 }
326
327 // Get the Center of Mass drift velocity.
328
329 getCOMVel(vdrift);
330
331 // Corrects for the center of mass drift.
332 // sums all the momentum and divides by total mass.
333
334 for(vd = 0; vd < nobj; vd++){
335
336 info->integrableObjects[vd]->getVel(aVel);
337
338 for (j=0; j < 3; j++)
339 aVel[j] -= vdrift[j];
340
341 info->integrableObjects[vd]->setVel( aVel );
342 }
343
344 }
345
346 void Thermo::getCOMVel(double vdrift[3]){
347
348 double mtot, mtot_local;
349 double aVel[3], amass;
350 double vdrift_local[3];
351 int vd, j;
352 int nobj;
353
354 nobj = info->integrableObjects.size();
355
356 mtot_local = 0.0;
357 vdrift_local[0] = 0.0;
358 vdrift_local[1] = 0.0;
359 vdrift_local[2] = 0.0;
360
361 for(vd = 0; vd < nobj; vd++){
362
363 amass = info->integrableObjects[vd]->getMass();
364 info->integrableObjects[vd]->getVel( aVel );
365
366 for(j = 0; j < 3; j++)
367 vdrift_local[j] += aVel[j] * amass;
368
369 mtot_local += amass;
370 }
371
372 #ifdef IS_MPI
373 MPI_Allreduce(&mtot_local,&mtot,1,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
374 MPI_Allreduce(vdrift_local,vdrift,3,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
375 #else
376 mtot = mtot_local;
377 for(vd = 0; vd < 3; vd++) {
378 vdrift[vd] = vdrift_local[vd];
379 }
380 #endif
381
382 for (vd = 0; vd < 3; vd++) {
383 vdrift[vd] = vdrift[vd] / mtot;
384 }
385
386 }
387
388 void Thermo::getCOM(double COM[3]){
389
390 double mtot, mtot_local;
391 double aPos[3], amass;
392 double COM_local[3];
393 int i, j;
394 int nobj;
395
396 mtot_local = 0.0;
397 COM_local[0] = 0.0;
398 COM_local[1] = 0.0;
399 COM_local[2] = 0.0;
400
401 nobj = info->integrableObjects.size();
402 for(i = 0; i < nobj; i++){
403
404 amass = info->integrableObjects[i]->getMass();
405 info->integrableObjects[i]->getPos( aPos );
406
407 for(j = 0; j < 3; j++)
408 COM_local[j] += aPos[j] * amass;
409
410 mtot_local += amass;
411 }
412
413 #ifdef IS_MPI
414 MPI_Allreduce(&mtot_local,&mtot,1,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
415 MPI_Allreduce(COM_local,COM,3,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
416 #else
417 mtot = mtot_local;
418 for(i = 0; i < 3; i++) {
419 COM[i] = COM_local[i];
420 }
421 #endif
422
423 for (i = 0; i < 3; i++) {
424 COM[i] = COM[i] / mtot;
425 }
426 }
427
428 void Thermo::removeCOMdrift() {
429 double vdrift[3], aVel[3];
430 int vd, j, nobj;
431
432 nobj = info->integrableObjects.size();
433
434 // Get the Center of Mass drift velocity.
435
436 getCOMVel(vdrift);
437
438 // Corrects for the center of mass drift.
439 // sums all the momentum and divides by total mass.
440
441 for(vd = 0; vd < nobj; vd++){
442
443 info->integrableObjects[vd]->getVel(aVel);
444
445 for (j=0; j < 3; j++)
446 aVel[j] -= vdrift[j];
447
448 info->integrableObjects[vd]->setVel( aVel );
449 }
450 }