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root/group/trunk/mdtools/md_code/Symplectic.cpp
Revision: 249
Committed: Mon Jan 27 21:28:19 2003 UTC (21 years, 5 months ago) by chuckv
File size: 15067 byte(s)
Log Message:
For some unknown reason the Single processor builds. Has not been tested!

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