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root/group/trunk/OOPSE/libmdtools/Symplectic.cpp
Revision: 497
Committed: Mon Apr 14 21:16:37 2003 UTC (21 years, 3 months ago) by chuckv
File size: 17321 byte(s)
Log Message:
Fixed ordering on NVT calculation in integrators.

File Contents

# Content
1 #include <iostream>
2 #include <cstdlib>
3
4 #include "Integrator.hpp"
5 #include "Thermo.hpp"
6 #include "ReadWrite.hpp"
7 #include "ForceFields.hpp"
8 #include "ExtendedSystem.hpp"
9 #include "simError.h"
10
11 extern "C"{
12
13 void v_constrain_a_( double &dt, int &n_atoms, double* mass,
14 double* Rx, double* Ry, double* Rz,
15 double* Vx, double* Vy, double* Vz,
16 double* Fx, double* Fy, double* Fz,
17 int &n_constrained, double *constr_sqr,
18 int* constr_i, int* constr_j,
19 double &box_x, double &box_y, double &box_z );
20
21 void v_constrain_b_( double &dt, int &n_atoms, double* mass,
22 double* Rx, double* Ry, double* Rz,
23 double* Vx, double* Vy, double* Vz,
24 double* Fx, double* Fy, double* Fz,
25 double &Kinetic,
26 int &n_constrained, double *constr_sqr,
27 int* constr_i, int* constr_j,
28 double &box_x, double &box_y, double &box_z );
29 }
30
31
32
33
34 Symplectic::Symplectic( SimInfo* the_entry_plug, ForceFields* the_ff,
35 ExtendedSystem* the_es ){
36 entry_plug = the_entry_plug;
37 myFF = the_ff;
38 myES = the_es;
39 isFirst = 1;
40
41 molecules = entry_plug->molecules;
42 nMols = entry_plug->n_mol;
43
44 // give a little love back to the SimInfo object
45
46 if( entry_plug->the_integrator != NULL ) delete entry_plug->the_integrator;
47 entry_plug->the_integrator = this;
48
49 // grab the masses
50
51 mass = new double[entry_plug->n_atoms];
52 for(int i = 0; i < entry_plug->n_atoms; i++){
53 mass[i] = entry_plug->atoms[i]->getMass();
54 }
55
56 // check for constraints
57
58 is_constrained = 0;
59
60 Constraint *temp_con;
61 Constraint *dummy_plug;
62 temp_con = new Constraint[entry_plug->n_SRI];
63 n_constrained = 0;
64 int constrained = 0;
65
66 SRI** theArray;
67 for(int i = 0; i < nMols; i++){
68
69 theArray = (SRI**) molecules[i].getMyBonds();
70 for(int j=0; j<molecules[i].getNBonds(); j++){
71
72 constrained = theArray[j]->is_constrained();
73
74 if(constrained){
75
76 dummy_plug = theArray[j]->get_constraint();
77 temp_con[n_constrained].set_a( dummy_plug->get_a() );
78 temp_con[n_constrained].set_b( dummy_plug->get_b() );
79 temp_con[n_constrained].set_dsqr( dummy_plug->get_dsqr() );
80
81 n_constrained++;
82 constrained = 0;
83 }
84 }
85
86 theArray = (SRI**) molecules[i].getMyBends();
87 for(int j=0; j<molecules[i].getNBends(); j++){
88
89 constrained = theArray[j]->is_constrained();
90
91 if(constrained){
92
93 dummy_plug = theArray[j]->get_constraint();
94 temp_con[n_constrained].set_a( dummy_plug->get_a() );
95 temp_con[n_constrained].set_b( dummy_plug->get_b() );
96 temp_con[n_constrained].set_dsqr( dummy_plug->get_dsqr() );
97
98 n_constrained++;
99 constrained = 0;
100 }
101 }
102
103 theArray = (SRI**) molecules[i].getMyTorsions();
104 for(int j=0; j<molecules[i].getNTorsions(); j++){
105
106 constrained = theArray[j]->is_constrained();
107
108 if(constrained){
109
110 dummy_plug = theArray[j]->get_constraint();
111 temp_con[n_constrained].set_a( dummy_plug->get_a() );
112 temp_con[n_constrained].set_b( dummy_plug->get_b() );
113 temp_con[n_constrained].set_dsqr( dummy_plug->get_dsqr() );
114
115 n_constrained++;
116 constrained = 0;
117 }
118 }
119 }
120
121 if(n_constrained > 0){
122
123 is_constrained = 1;
124 constrained_i = new int[n_constrained];
125 constrained_j = new int[n_constrained];
126 constrained_dsqr = new double[n_constrained];
127
128 for( int i = 0; i < n_constrained; i++){
129
130 /* add 1 to the index for the fortran arrays. */
131
132 constrained_i[i] = temp_con[i].get_a() + 1;
133 constrained_j[i] = temp_con[i].get_b() + 1;
134 constrained_dsqr[i] = temp_con[i].get_dsqr();
135 }
136 }
137
138 delete[] temp_con;
139 }
140
141 Symplectic::~Symplectic() {
142
143 if( n_constrained ){
144 delete[] constrained_i;
145 delete[] constrained_j;
146 delete[] constrained_dsqr;
147 }
148
149 }
150
151
152 void Symplectic::integrate( void ){
153
154 const double e_convert = 4.184e-4; // converts kcal/mol -> amu*A^2/fs^2
155
156 int i, j; // loop counters
157 int nAtoms = entry_plug->n_atoms; // the number of atoms
158 double kE = 0.0; // the kinetic energy
159 double rot_kE;
160 double trans_kE;
161 int tl; // the time loop conter
162 double dt2; // half the dt
163
164 double vx, vy, vz; // the velocities
165 double vx2, vy2, vz2; // the square of the velocities
166 double rx, ry, rz; // the postitions
167
168 double ji[3]; // the body frame angular momentum
169 double jx2, jy2, jz2; // the square of the angular momentums
170 double Tb[3]; // torque in the body frame
171 double angle; // the angle through which to rotate the rotation matrix
172 double A[3][3]; // the rotation matrix
173 double press[9];
174
175 int time;
176
177 double dt = entry_plug->dt;
178 double runTime = entry_plug->run_time;
179 double sampleTime = entry_plug->sampleTime;
180 double statusTime = entry_plug->statusTime;
181 double thermalTime = entry_plug->thermalTime;
182
183 int n_loops = (int)( runTime / dt );
184 int sample_n = (int)( sampleTime / dt );
185 int status_n = (int)( statusTime / dt );
186 int vel_n = (int)( thermalTime / dt );
187
188 int calcPot, calcStress;
189
190 Thermo *tStats;
191 StatWriter* e_out;
192 DumpWriter* dump_out;
193
194 tStats = new Thermo( entry_plug );
195 e_out = new StatWriter( entry_plug );
196 dump_out = new DumpWriter( entry_plug );
197
198 Atom** atoms = entry_plug->atoms;
199 DirectionalAtom* dAtom;
200 dt2 = 0.5 * dt;
201
202 // initialize the forces the before the first step
203
204 myFF->doForces(1,1);
205
206 if( entry_plug->setTemp ){
207
208 tStats->velocitize();
209 }
210
211 dump_out->writeDump( 0.0 );
212 e_out->writeStat( 0.0 );
213
214 calcPot = 0;
215
216 if (!strcasecmp( entry_plug->ensemble, "NPT")) {
217 calcStress = 1;
218 } else {
219 calcStress = 0;
220 }
221
222 if( n_constrained ){
223
224 double *Rx = new double[nAtoms];
225 double *Ry = new double[nAtoms];
226 double *Rz = new double[nAtoms];
227
228 double *Vx = new double[nAtoms];
229 double *Vy = new double[nAtoms];
230 double *Vz = new double[nAtoms];
231
232 double *Fx = new double[nAtoms];
233 double *Fy = new double[nAtoms];
234 double *Fz = new double[nAtoms];
235
236
237 for( tl=0; tl < n_loops; tl++ ){
238
239
240 for( j=0; j<nAtoms; j++ ){
241
242 Rx[j] = atoms[j]->getX();
243 Ry[j] = atoms[j]->getY();
244 Rz[j] = atoms[j]->getZ();
245
246 Vx[j] = atoms[j]->get_vx();
247 Vy[j] = atoms[j]->get_vy();
248 Vz[j] = atoms[j]->get_vz();
249
250 Fx[j] = atoms[j]->getFx();
251 Fy[j] = atoms[j]->getFy();
252 Fz[j] = atoms[j]->getFz();
253
254 }
255
256 v_constrain_a_( dt, nAtoms, mass, Rx, Ry, Rz, Vx, Vy, Vz,
257 Fx, Fy, Fz,
258 n_constrained, constrained_dsqr,
259 constrained_i, constrained_j,
260 entry_plug->box_x,
261 entry_plug->box_y,
262 entry_plug->box_z );
263
264 for( j=0; j<nAtoms; j++ ){
265
266 atoms[j]->setX(Rx[j]);
267 atoms[j]->setY(Ry[j]);
268 atoms[j]->setZ(Rz[j]);
269
270 atoms[j]->set_vx(Vx[j]);
271 atoms[j]->set_vy(Vy[j]);
272 atoms[j]->set_vz(Vz[j]);
273 }
274
275
276 for( i=0; i<nAtoms; i++ ){
277 if( atoms[i]->isDirectional() ){
278
279 dAtom = (DirectionalAtom *)atoms[i];
280
281 // get and convert the torque to body frame
282
283 Tb[0] = dAtom->getTx();
284 Tb[1] = dAtom->getTy();
285 Tb[2] = dAtom->getTz();
286
287 dAtom->lab2Body( Tb );
288
289 // get the angular momentum, and propagate a half step
290
291 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
292 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
293 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
294
295 // get the atom's rotation matrix
296
297 A[0][0] = dAtom->getAxx();
298 A[0][1] = dAtom->getAxy();
299 A[0][2] = dAtom->getAxz();
300
301 A[1][0] = dAtom->getAyx();
302 A[1][1] = dAtom->getAyy();
303 A[1][2] = dAtom->getAyz();
304
305 A[2][0] = dAtom->getAzx();
306 A[2][1] = dAtom->getAzy();
307 A[2][2] = dAtom->getAzz();
308
309
310 // use the angular velocities to propagate the rotation matrix a
311 // full time step
312
313
314 angle = dt2 * ji[0] / dAtom->getIxx();
315 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
316
317 angle = dt2 * ji[1] / dAtom->getIyy();
318 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
319
320 angle = dt * ji[2] / dAtom->getIzz();
321 this->rotate( 0, 1, angle, ji, A ); // rotate about the z-axis
322
323 angle = dt2 * ji[1] / dAtom->getIyy();
324 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
325
326 angle = dt2 * ji[0] / dAtom->getIxx();
327 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
328
329
330 dAtom->setA( A );
331 dAtom->setJx( ji[0] );
332 dAtom->setJy( ji[1] );
333 dAtom->setJz( ji[2] );
334 }
335 }
336
337 if (!strcasecmp( entry_plug->ensemble, "NVT"))
338 myES->NoseHooverNVT( dt / 2.0 , tStats->getKinetic() );
339
340 // calculate the forces
341
342 myFF->doForces(calcPot, calcStress);
343
344 // move b
345
346 for( j=0; j<nAtoms; j++ ){
347
348 Rx[j] = atoms[j]->getX();
349 Ry[j] = atoms[j]->getY();
350 Rz[j] = atoms[j]->getZ();
351
352 Vx[j] = atoms[j]->get_vx();
353 Vy[j] = atoms[j]->get_vy();
354 Vz[j] = atoms[j]->get_vz();
355
356 Fx[j] = atoms[j]->getFx();
357 Fy[j] = atoms[j]->getFy();
358 Fz[j] = atoms[j]->getFz();
359 }
360
361 v_constrain_b_( dt, nAtoms, mass, Rx, Ry, Rz, Vx, Vy, Vz,
362 Fx, Fy, Fz,
363 kE, n_constrained, constrained_dsqr,
364 constrained_i, constrained_j,
365 entry_plug->box_x,
366 entry_plug->box_y,
367 entry_plug->box_z );
368
369 for( j=0; j<nAtoms; j++ ){
370
371 atoms[j]->setX(Rx[j]);
372 atoms[j]->setY(Ry[j]);
373 atoms[j]->setZ(Rz[j]);
374
375 atoms[j]->set_vx(Vx[j]);
376 atoms[j]->set_vy(Vy[j]);
377 atoms[j]->set_vz(Vz[j]);
378 }
379
380 for( i=0; i< nAtoms; i++ ){
381
382 if( atoms[i]->isDirectional() ){
383
384 dAtom = (DirectionalAtom *)atoms[i];
385
386 // get and convert the torque to body frame
387
388 Tb[0] = dAtom->getTx();
389 Tb[1] = dAtom->getTy();
390 Tb[2] = dAtom->getTz();
391
392 dAtom->lab2Body( Tb );
393
394 // get the angular momentum, and complete the angular momentum
395 // half step
396
397 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
398 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
399 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
400
401 dAtom->setJx( ji[0] );
402 dAtom->setJy( ji[1] );
403 dAtom->setJz( ji[2] );
404 }
405 }
406
407
408 if (!strcasecmp( entry_plug->ensemble, "NVT"))
409 myES->NoseHooverNVT( dt / 2.0, tStats->getKinetic() );
410
411 if (!strcasecmp( entry_plug->ensemble, "NPT") ) {
412 tStats->getPressureTensor(press);
413 myES->NoseHooverAndersonNPT( dt,
414 tStats->getKinetic(),
415 press);
416 }
417
418 time = tl + 1;
419
420 if( entry_plug->setTemp ){
421 if( !(time % vel_n) ) tStats->velocitize();
422 }
423 if( !(time % sample_n) ) dump_out->writeDump( time * dt );
424 if( !((time+1) % status_n) ) {
425 calcPot = 1;
426 calcStress = 1;
427 }
428 if( !(time % status_n) ){
429 e_out->writeStat( time * dt );
430 calcPot = 0;
431 if (!strcasecmp(entry_plug->ensemble, "NPT")) calcStress = 1;
432 else calcStress = 0;
433 }
434 }
435 }
436 else{
437
438 for( tl=0; tl<n_loops; tl++ ){
439
440 kE = 0.0;
441 rot_kE= 0.0;
442 trans_kE = 0.0;
443
444 for( i=0; i<nAtoms; i++ ){
445
446 // velocity half step
447
448 vx = atoms[i]->get_vx() +
449 ( dt2 * atoms[i]->getFx() / atoms[i]->getMass() ) * e_convert;
450 vy = atoms[i]->get_vy() +
451 ( dt2 * atoms[i]->getFy() / atoms[i]->getMass() ) * e_convert;
452 vz = atoms[i]->get_vz() +
453 ( dt2 * atoms[i]->getFz() / atoms[i]->getMass() ) * e_convert;
454
455 // position whole step
456
457 rx = atoms[i]->getX() + dt * vx;
458 ry = atoms[i]->getY() + dt * vy;
459 rz = atoms[i]->getZ() + dt * vz;
460
461 atoms[i]->setX( rx );
462 atoms[i]->setY( ry );
463 atoms[i]->setZ( rz );
464
465 atoms[i]->set_vx( vx );
466 atoms[i]->set_vy( vy );
467 atoms[i]->set_vz( vz );
468
469 if( atoms[i]->isDirectional() ){
470
471 dAtom = (DirectionalAtom *)atoms[i];
472
473 // get and convert the torque to body frame
474
475 Tb[0] = dAtom->getTx();
476 Tb[1] = dAtom->getTy();
477 Tb[2] = dAtom->getTz();
478
479 dAtom->lab2Body( Tb );
480
481 // get the angular momentum, and propagate a half step
482
483 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
484 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
485 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
486
487 // get the atom's rotation matrix
488
489 A[0][0] = dAtom->getAxx();
490 A[0][1] = dAtom->getAxy();
491 A[0][2] = dAtom->getAxz();
492
493 A[1][0] = dAtom->getAyx();
494 A[1][1] = dAtom->getAyy();
495 A[1][2] = dAtom->getAyz();
496
497 A[2][0] = dAtom->getAzx();
498 A[2][1] = dAtom->getAzy();
499 A[2][2] = dAtom->getAzz();
500
501
502 // use the angular velocities to propagate the rotation matrix a
503 // full time step
504
505
506 angle = dt2 * ji[0] / dAtom->getIxx();
507 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
508
509 angle = dt2 * ji[1] / dAtom->getIyy();
510 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
511
512 angle = dt * ji[2] / dAtom->getIzz();
513 this->rotate( 0, 1, angle, ji, A ); // rotate about the z-axis
514
515 angle = dt2 * ji[1] / dAtom->getIyy();
516 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
517
518 angle = dt2 * ji[0] / dAtom->getIxx();
519 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
520
521
522 dAtom->setA( A );
523 dAtom->setJx( ji[0] );
524 dAtom->setJy( ji[1] );
525 dAtom->setJz( ji[2] );
526 }
527 }
528
529 if (!strcasecmp( entry_plug->ensemble, "NVT"))
530 myES->NoseHooverNVT( dt / 2.0, tStats->getKinetic() );
531
532
533 // calculate the forces
534
535 myFF->doForces(calcPot,calcStress);
536
537 for( i=0; i< nAtoms; i++ ){
538
539 // complete the velocity half step
540
541 vx = atoms[i]->get_vx() +
542 ( dt2 * atoms[i]->getFx() / atoms[i]->getMass() ) * e_convert;
543 vy = atoms[i]->get_vy() +
544 ( dt2 * atoms[i]->getFy() / atoms[i]->getMass() ) * e_convert;
545 vz = atoms[i]->get_vz() +
546 ( dt2 * atoms[i]->getFz() / atoms[i]->getMass() ) * e_convert;
547
548 atoms[i]->set_vx( vx );
549 atoms[i]->set_vy( vy );
550 atoms[i]->set_vz( vz );
551
552 vx2 = vx * vx;
553 vy2 = vy * vy;
554 vz2 = vz * vz;
555
556 if( atoms[i]->isDirectional() ){
557
558 dAtom = (DirectionalAtom *)atoms[i];
559
560 // get and convert the torque to body frame
561
562 Tb[0] = dAtom->getTx();
563 Tb[1] = dAtom->getTy();
564 Tb[2] = dAtom->getTz();
565
566 dAtom->lab2Body( Tb );
567
568 // get the angular momentum, and complete the angular momentum
569 // half step
570
571 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
572 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
573 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
574
575 jx2 = ji[0] * ji[0];
576 jy2 = ji[1] * ji[1];
577 jz2 = ji[2] * ji[2];
578
579 rot_kE += (jx2 / dAtom->getIxx()) + (jy2 / dAtom->getIyy())
580 + (jz2 / dAtom->getIzz());
581
582 dAtom->setJx( ji[0] );
583 dAtom->setJy( ji[1] );
584 dAtom->setJz( ji[2] );
585 }
586
587 }
588
589 if (!strcasecmp( entry_plug->ensemble, "NVT"))
590 myES->NoseHooverNVT( dt / 2.0, tStats->getKinetic() );
591
592 if (!strcasecmp( entry_plug->ensemble, "NPT") ) {
593 tStats->getPressureTensor(press);
594 myES->NoseHooverAndersonNPT( dt,
595 tStats->getKinetic(),
596 press);
597 }
598
599 time = tl + 1;
600
601 if( entry_plug->setTemp ){
602 if( !(time % vel_n) ) tStats->velocitize();
603 }
604 if( !(time % sample_n) ) dump_out->writeDump( time * dt );
605 if( !((time+1) % status_n) ) {
606 calcPot = 1;
607 calcStress = 1;
608 }
609 if( !(time % status_n) ){
610 e_out->writeStat( time * dt );
611 calcPot = 0;
612 if (!strcasecmp(entry_plug->ensemble, "NPT")) calcStress = 1;
613 else calcStress = 0;
614 }
615 }
616 }
617
618 dump_out->writeFinal();
619
620 delete dump_out;
621 delete e_out;
622 }
623
624 void Symplectic::rotate( int axes1, int axes2, double angle, double ji[3],
625 double A[3][3] ){
626
627 int i,j,k;
628 double sinAngle;
629 double cosAngle;
630 double angleSqr;
631 double angleSqrOver4;
632 double top, bottom;
633 double rot[3][3];
634 double tempA[3][3];
635 double tempJ[3];
636
637 // initialize the tempA
638
639 for(i=0; i<3; i++){
640 for(j=0; j<3; j++){
641 tempA[j][i] = A[i][j];
642 }
643 }
644
645 // initialize the tempJ
646
647 for( i=0; i<3; i++) tempJ[i] = ji[i];
648
649 // initalize rot as a unit matrix
650
651 rot[0][0] = 1.0;
652 rot[0][1] = 0.0;
653 rot[0][2] = 0.0;
654
655 rot[1][0] = 0.0;
656 rot[1][1] = 1.0;
657 rot[1][2] = 0.0;
658
659 rot[2][0] = 0.0;
660 rot[2][1] = 0.0;
661 rot[2][2] = 1.0;
662
663 // use a small angle aproximation for sin and cosine
664
665 angleSqr = angle * angle;
666 angleSqrOver4 = angleSqr / 4.0;
667 top = 1.0 - angleSqrOver4;
668 bottom = 1.0 + angleSqrOver4;
669
670 cosAngle = top / bottom;
671 sinAngle = angle / bottom;
672
673 rot[axes1][axes1] = cosAngle;
674 rot[axes2][axes2] = cosAngle;
675
676 rot[axes1][axes2] = sinAngle;
677 rot[axes2][axes1] = -sinAngle;
678
679 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
680
681 for(i=0; i<3; i++){
682 ji[i] = 0.0;
683 for(k=0; k<3; k++){
684 ji[i] += rot[i][k] * tempJ[k];
685 }
686 }
687
688 // rotate the Rotation matrix acording to:
689 // A[][] = A[][] * transpose(rot[][])
690
691
692 // NOte for as yet unknown reason, we are setting the performing the
693 // calculation as:
694 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
695
696 for(i=0; i<3; i++){
697 for(j=0; j<3; j++){
698 A[j][i] = 0.0;
699 for(k=0; k<3; k++){
700 A[j][i] += tempA[i][k] * rot[j][k];
701 }
702 }
703 }
704 }