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root/group/trunk/OOPSE/libmdtools/Symplectic.cpp
Revision: 466
Committed: Mon Apr 7 14:30:36 2003 UTC (21 years, 3 months ago) by gezelter
File size: 15863 byte(s)
Log Message:
Added ExtendedSystem infrastructure for NPT and NVT calculations

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
174 int time;
175
176 double dt = entry_plug->dt;
177 double runTime = entry_plug->run_time;
178 double sampleTime = entry_plug->sampleTime;
179 double statusTime = entry_plug->statusTime;
180 double thermalTime = entry_plug->thermalTime;
181
182 int n_loops = (int)( runTime / dt );
183 int sample_n = (int)( sampleTime / dt );
184 int status_n = (int)( statusTime / dt );
185 int vel_n = (int)( thermalTime / dt );
186
187 int calcPot;
188
189 Thermo *tStats = new Thermo( entry_plug );
190
191 StatWriter* e_out = new StatWriter( entry_plug );
192 DumpWriter* dump_out = new DumpWriter( entry_plug );
193
194 Atom** atoms = entry_plug->atoms;
195 DirectionalAtom* dAtom;
196 dt2 = 0.5 * dt;
197
198 // initialize the forces the before the first step
199
200 myFF->doForces(1,0);
201
202 if( entry_plug->setTemp ){
203
204 tStats->velocitize();
205 }
206
207 dump_out->writeDump( 0.0 );
208 e_out->writeStat( 0.0 );
209
210 calcPot = 0;
211
212 if( n_constrained ){
213
214 double *Rx = new double[nAtoms];
215 double *Ry = new double[nAtoms];
216 double *Rz = new double[nAtoms];
217
218 double *Vx = new double[nAtoms];
219 double *Vy = new double[nAtoms];
220 double *Vz = new double[nAtoms];
221
222 double *Fx = new double[nAtoms];
223 double *Fy = new double[nAtoms];
224 double *Fz = new double[nAtoms];
225
226
227 for( tl=0; tl < n_loops; tl++ ){
228
229 for( j=0; j<nAtoms; j++ ){
230
231 Rx[j] = atoms[j]->getX();
232 Ry[j] = atoms[j]->getY();
233 Rz[j] = atoms[j]->getZ();
234
235 Vx[j] = atoms[j]->get_vx();
236 Vy[j] = atoms[j]->get_vy();
237 Vz[j] = atoms[j]->get_vz();
238
239 Fx[j] = atoms[j]->getFx();
240 Fy[j] = atoms[j]->getFy();
241 Fz[j] = atoms[j]->getFz();
242
243 }
244
245 v_constrain_a_( dt, nAtoms, mass, Rx, Ry, Rz, Vx, Vy, Vz,
246 Fx, Fy, Fz,
247 n_constrained, constrained_dsqr,
248 constrained_i, constrained_j,
249 entry_plug->box_x,
250 entry_plug->box_y,
251 entry_plug->box_z );
252
253 for( j=0; j<nAtoms; j++ ){
254
255 atoms[j]->setX(Rx[j]);
256 atoms[j]->setY(Ry[j]);
257 atoms[j]->setZ(Rz[j]);
258
259 atoms[j]->set_vx(Vx[j]);
260 atoms[j]->set_vy(Vy[j]);
261 atoms[j]->set_vz(Vz[j]);
262 }
263
264
265 for( i=0; i<nAtoms; i++ ){
266 if( atoms[i]->isDirectional() ){
267
268 dAtom = (DirectionalAtom *)atoms[i];
269
270 // get and convert the torque to body frame
271
272 Tb[0] = dAtom->getTx();
273 Tb[1] = dAtom->getTy();
274 Tb[2] = dAtom->getTz();
275
276 dAtom->lab2Body( Tb );
277
278 // get the angular momentum, and propagate a half step
279
280 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
281 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
282 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
283
284 // get the atom's rotation matrix
285
286 A[0][0] = dAtom->getAxx();
287 A[0][1] = dAtom->getAxy();
288 A[0][2] = dAtom->getAxz();
289
290 A[1][0] = dAtom->getAyx();
291 A[1][1] = dAtom->getAyy();
292 A[1][2] = dAtom->getAyz();
293
294 A[2][0] = dAtom->getAzx();
295 A[2][1] = dAtom->getAzy();
296 A[2][2] = dAtom->getAzz();
297
298
299 // use the angular velocities to propagate the rotation matrix a
300 // full time step
301
302
303 angle = dt2 * ji[0] / dAtom->getIxx();
304 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
305
306 angle = dt2 * ji[1] / dAtom->getIyy();
307 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
308
309 angle = dt * ji[2] / dAtom->getIzz();
310 this->rotate( 0, 1, angle, ji, A ); // rotate about the z-axis
311
312 angle = dt2 * ji[1] / dAtom->getIyy();
313 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
314
315 angle = dt2 * ji[0] / dAtom->getIxx();
316 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
317
318
319 dAtom->setA( A );
320 dAtom->setJx( ji[0] );
321 dAtom->setJy( ji[1] );
322 dAtom->setJz( ji[2] );
323 }
324 }
325
326 // calculate the forces
327
328 myFF->doForces(calcPot, 0);
329
330 // move b
331
332 for( j=0; j<nAtoms; j++ ){
333
334 Rx[j] = atoms[j]->getX();
335 Ry[j] = atoms[j]->getY();
336 Rz[j] = atoms[j]->getZ();
337
338 Vx[j] = atoms[j]->get_vx();
339 Vy[j] = atoms[j]->get_vy();
340 Vz[j] = atoms[j]->get_vz();
341
342 Fx[j] = atoms[j]->getFx();
343 Fy[j] = atoms[j]->getFy();
344 Fz[j] = atoms[j]->getFz();
345 }
346
347 v_constrain_b_( dt, nAtoms, mass, Rx, Ry, Rz, Vx, Vy, Vz,
348 Fx, Fy, Fz,
349 kE, n_constrained, constrained_dsqr,
350 constrained_i, constrained_j,
351 entry_plug->box_x,
352 entry_plug->box_y,
353 entry_plug->box_z );
354
355 for( j=0; j<nAtoms; j++ ){
356
357 atoms[j]->setX(Rx[j]);
358 atoms[j]->setY(Ry[j]);
359 atoms[j]->setZ(Rz[j]);
360
361 atoms[j]->set_vx(Vx[j]);
362 atoms[j]->set_vy(Vy[j]);
363 atoms[j]->set_vz(Vz[j]);
364 }
365
366 for( i=0; i< nAtoms; i++ ){
367
368 if( atoms[i]->isDirectional() ){
369
370 dAtom = (DirectionalAtom *)atoms[i];
371
372 // get and convert the torque to body frame
373
374 Tb[0] = dAtom->getTx();
375 Tb[1] = dAtom->getTy();
376 Tb[2] = dAtom->getTz();
377
378 dAtom->lab2Body( Tb );
379
380 // get the angular momentum, and complete the angular momentum
381 // half step
382
383 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
384 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
385 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
386
387 dAtom->setJx( ji[0] );
388 dAtom->setJy( ji[1] );
389 dAtom->setJz( ji[2] );
390 }
391 }
392
393 time = tl + 1;
394
395 if( entry_plug->setTemp ){
396 if( !(time % vel_n) ) tStats->velocitize();
397 }
398 if( !(time % sample_n) ) dump_out->writeDump( time * dt );
399 if( !((time+1) % status_n) ) calcPot = 1;
400 if( !(time % status_n) ){ e_out->writeStat( time * dt ); calcPot = 0; }
401 }
402 }
403 else{
404
405 for( tl=0; tl<n_loops; tl++ ){
406
407 kE = 0.0;
408 rot_kE= 0.0;
409 trans_kE = 0.0;
410
411 for( i=0; i<nAtoms; i++ ){
412
413 // velocity half step
414
415 vx = atoms[i]->get_vx() +
416 ( dt2 * atoms[i]->getFx() / atoms[i]->getMass() ) * e_convert;
417 vy = atoms[i]->get_vy() +
418 ( dt2 * atoms[i]->getFy() / atoms[i]->getMass() ) * e_convert;
419 vz = atoms[i]->get_vz() +
420 ( dt2 * atoms[i]->getFz() / atoms[i]->getMass() ) * e_convert;
421
422 // position whole step
423
424 rx = atoms[i]->getX() + dt * vx;
425 ry = atoms[i]->getY() + dt * vy;
426 rz = atoms[i]->getZ() + dt * vz;
427
428 atoms[i]->setX( rx );
429 atoms[i]->setY( ry );
430 atoms[i]->setZ( rz );
431
432 atoms[i]->set_vx( vx );
433 atoms[i]->set_vy( vy );
434 atoms[i]->set_vz( vz );
435
436 if( atoms[i]->isDirectional() ){
437
438 dAtom = (DirectionalAtom *)atoms[i];
439
440 // get and convert the torque to body frame
441
442 Tb[0] = dAtom->getTx();
443 Tb[1] = dAtom->getTy();
444 Tb[2] = dAtom->getTz();
445
446 dAtom->lab2Body( Tb );
447
448 // get the angular momentum, and propagate a half step
449
450 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
451 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
452 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
453
454 // get the atom's rotation matrix
455
456 A[0][0] = dAtom->getAxx();
457 A[0][1] = dAtom->getAxy();
458 A[0][2] = dAtom->getAxz();
459
460 A[1][0] = dAtom->getAyx();
461 A[1][1] = dAtom->getAyy();
462 A[1][2] = dAtom->getAyz();
463
464 A[2][0] = dAtom->getAzx();
465 A[2][1] = dAtom->getAzy();
466 A[2][2] = dAtom->getAzz();
467
468
469 // use the angular velocities to propagate the rotation matrix a
470 // full time step
471
472
473 angle = dt2 * ji[0] / dAtom->getIxx();
474 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
475
476 angle = dt2 * ji[1] / dAtom->getIyy();
477 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
478
479 angle = dt * ji[2] / dAtom->getIzz();
480 this->rotate( 0, 1, angle, ji, A ); // rotate about the z-axis
481
482 angle = dt2 * ji[1] / dAtom->getIyy();
483 this->rotate( 2, 0, angle, ji, A ); // rotate about the y-axis
484
485 angle = dt2 * ji[0] / dAtom->getIxx();
486 this->rotate( 1, 2, angle, ji, A ); // rotate about the x-axis
487
488
489 dAtom->setA( A );
490 dAtom->setJx( ji[0] );
491 dAtom->setJy( ji[1] );
492 dAtom->setJz( ji[2] );
493 }
494 }
495
496 // calculate the forces
497
498 myFF->doForces(calcPot,0);
499
500 for( i=0; i< nAtoms; i++ ){
501
502 // complete the velocity half step
503
504 vx = atoms[i]->get_vx() +
505 ( dt2 * atoms[i]->getFx() / atoms[i]->getMass() ) * e_convert;
506 vy = atoms[i]->get_vy() +
507 ( dt2 * atoms[i]->getFy() / atoms[i]->getMass() ) * e_convert;
508 vz = atoms[i]->get_vz() +
509 ( dt2 * atoms[i]->getFz() / atoms[i]->getMass() ) * e_convert;
510
511 atoms[i]->set_vx( vx );
512 atoms[i]->set_vy( vy );
513 atoms[i]->set_vz( vz );
514
515 // vx2 = vx * vx;
516 // vy2 = vy * vy;
517 // vz2 = vz * vz;
518
519 if( atoms[i]->isDirectional() ){
520
521 dAtom = (DirectionalAtom *)atoms[i];
522
523 // get and convert the torque to body frame
524
525 Tb[0] = dAtom->getTx();
526 Tb[1] = dAtom->getTy();
527 Tb[2] = dAtom->getTz();
528
529 dAtom->lab2Body( Tb );
530
531 // get the angular momentum, and complete the angular momentum
532 // half step
533
534 ji[0] = dAtom->getJx() + ( dt2 * Tb[0] ) * e_convert;
535 ji[1] = dAtom->getJy() + ( dt2 * Tb[1] ) * e_convert;
536 ji[2] = dAtom->getJz() + ( dt2 * Tb[2] ) * e_convert;
537
538 jx2 = ji[0] * ji[0];
539 jy2 = ji[1] * ji[1];
540 jz2 = ji[2] * ji[2];
541
542 rot_kE += (jx2 / dAtom->getIxx()) + (jy2 / dAtom->getIyy())
543 + (jz2 / dAtom->getIzz());
544
545 dAtom->setJx( ji[0] );
546 dAtom->setJy( ji[1] );
547 dAtom->setJz( ji[2] );
548 }
549 }
550
551 time = tl + 1;
552
553 if( entry_plug->setTemp ){
554 if( !(time % vel_n) ) tStats->velocitize();
555 }
556 if( !(time % sample_n) ) dump_out->writeDump( time * dt );
557 if( !((time+1) % status_n) ) calcPot = 1;
558 if( !(time % status_n) ){ e_out->writeStat( time * dt ); calcPot = 0; }
559 }
560 }
561
562 dump_out->writeFinal();
563
564 delete dump_out;
565 delete e_out;
566 }
567
568 void Symplectic::rotate( int axes1, int axes2, double angle, double ji[3],
569 double A[3][3] ){
570
571 int i,j,k;
572 double sinAngle;
573 double cosAngle;
574 double angleSqr;
575 double angleSqrOver4;
576 double top, bottom;
577 double rot[3][3];
578 double tempA[3][3];
579 double tempJ[3];
580
581 // initialize the tempA
582
583 for(i=0; i<3; i++){
584 for(j=0; j<3; j++){
585 tempA[j][i] = A[i][j];
586 }
587 }
588
589 // initialize the tempJ
590
591 for( i=0; i<3; i++) tempJ[i] = ji[i];
592
593 // initalize rot as a unit matrix
594
595 rot[0][0] = 1.0;
596 rot[0][1] = 0.0;
597 rot[0][2] = 0.0;
598
599 rot[1][0] = 0.0;
600 rot[1][1] = 1.0;
601 rot[1][2] = 0.0;
602
603 rot[2][0] = 0.0;
604 rot[2][1] = 0.0;
605 rot[2][2] = 1.0;
606
607 // use a small angle aproximation for sin and cosine
608
609 angleSqr = angle * angle;
610 angleSqrOver4 = angleSqr / 4.0;
611 top = 1.0 - angleSqrOver4;
612 bottom = 1.0 + angleSqrOver4;
613
614 cosAngle = top / bottom;
615 sinAngle = angle / bottom;
616
617 rot[axes1][axes1] = cosAngle;
618 rot[axes2][axes2] = cosAngle;
619
620 rot[axes1][axes2] = sinAngle;
621 rot[axes2][axes1] = -sinAngle;
622
623 // rotate the momentum acoording to: ji[] = rot[][] * ji[]
624
625 for(i=0; i<3; i++){
626 ji[i] = 0.0;
627 for(k=0; k<3; k++){
628 ji[i] += rot[i][k] * tempJ[k];
629 }
630 }
631
632 // rotate the Rotation matrix acording to:
633 // A[][] = A[][] * transpose(rot[][])
634
635
636 // NOte for as yet unknown reason, we are setting the performing the
637 // calculation as:
638 // transpose(A[][]) = transpose(A[][]) * transpose(rot[][])
639
640 for(i=0; i<3; i++){
641 for(j=0; j<3; j++){
642 A[j][i] = 0.0;
643 for(k=0; k<3; k++){
644 A[j][i] += tempA[i][k] * rot[j][k];
645 }
646 }
647 }
648 }