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root/group/trunk/OOPSE/libmdtools/Verlet.cpp
Revision: 475
Committed: Tue Apr 8 12:44:18 2003 UTC (21 years, 3 months ago) by gezelter
File size: 11413 byte(s)
Log Message:
Changes to integrate the NVT and NPT ensembles

File Contents

# User Rev Content
1 mmeineke 377 #include <iostream>
2     #include <stdlib.h>
3    
4     #include "Atom.hpp"
5     #include "SRI.hpp"
6     #include "Integrator.hpp"
7     #include "SimInfo.hpp"
8     #include "Thermo.hpp"
9     #include "ReadWrite.hpp"
10 gezelter 466 #include "ExtendedSystem.hpp"
11 mmeineke 377
12     extern "C"{
13    
14     void v_constrain_a_( double &dt, int &n_atoms, double* mass,
15     double* Rx, double* Ry, double* Rz,
16     double* Vx, double* Vy, double* Vz,
17     double* Fx, double* Fy, double* Fz,
18     int &n_constrained, double *constr_sqr,
19     int* constr_i, int* constr_j,
20     double &box_x, double &box_y, double &box_z );
21    
22     void v_constrain_b_( double &dt, int &n_atoms, double* mass,
23     double* Rx, double* Ry, double* Rz,
24     double* Vx, double* Vy, double* Vz,
25     double* Fx, double* Fy, double* Fz,
26     double &Kinetic,
27     int &n_constrained, double *constr_sqr,
28     int* constr_i, int* constr_j,
29     double &box_x, double &box_y, double &box_z );
30     }
31    
32    
33 gezelter 466 Verlet::Verlet( SimInfo &info, ForceFields* the_ff, ExtendedSystem* the_es ){
34 mmeineke 377
35     // get what information we need from the SimInfo object
36    
37     entry_plug = &info;
38     myFF = the_ff;
39 gezelter 466 myES = the_es;
40 mmeineke 423
41 mmeineke 377 c_natoms = info.n_atoms;
42     c_atoms = info.atoms;
43 mmeineke 423 nMols = info.n_mol;
44     molecules = info.molecules;
45 mmeineke 377 c_is_constrained = 0;
46     c_box_x = info.box_x;
47     c_box_y = info.box_y;
48     c_box_z = info.box_z;
49    
50     // give a little love back to the SimInfo object
51    
52     if( info.the_integrator != NULL ) delete info.the_integrator;
53     info.the_integrator = this;
54    
55     // the rest are initialization issues
56    
57     is_first = 1; // let the integrate method know when the first call is
58    
59     // mass array setup
60    
61     c_mass = new double[c_natoms];
62    
63     for(int i = 0; i < c_natoms; i++){
64     c_mass[i] = c_atoms[i]->getMass();
65     }
66    
67     // check for constraints
68    
69     Constraint *temp_con;
70     Constraint *dummy_plug;
71 mmeineke 423 temp_con = new Constraint[info.n_SRI];
72 mmeineke 377
73     c_n_constrained = 0;
74     int constrained = 0;
75 mmeineke 423 SRI** theArray;
76     for(int i = 0; i < nMols; i++){
77 mmeineke 377
78 mmeineke 428 theArray = (SRI**) molecules[i].getMyBonds();
79     for(int j=0; j<molecules[i].getNBonds(); j++){
80 mmeineke 423
81     constrained = theArray[j]->is_constrained();
82    
83     if(constrained){
84    
85     dummy_plug = theArray[j]->get_constraint();
86     temp_con[c_n_constrained].set_a( dummy_plug->get_a() );
87     temp_con[c_n_constrained].set_b( dummy_plug->get_b() );
88     temp_con[c_n_constrained].set_dsqr( dummy_plug->get_dsqr() );
89    
90     c_n_constrained++;
91     constrained = 0;
92     }
93     }
94 mmeineke 377
95 mmeineke 428 theArray = (SRI**) molecules[i].getMyBends();
96     for(int j=0; j<molecules[i].getNBends(); j++){
97 mmeineke 377
98 mmeineke 423 constrained = theArray[j]->is_constrained();
99    
100     if(constrained){
101    
102     dummy_plug = theArray[j]->get_constraint();
103     temp_con[c_n_constrained].set_a( dummy_plug->get_a() );
104     temp_con[c_n_constrained].set_b( dummy_plug->get_b() );
105     temp_con[c_n_constrained].set_dsqr( dummy_plug->get_dsqr() );
106    
107     c_n_constrained++;
108     constrained = 0;
109     }
110     }
111 mmeineke 377
112 mmeineke 428 theArray = (SRI**) molecules[i].getMyTorsions();
113     for(int j=0; j<molecules[i].getNTorsions(); j++){
114 mmeineke 423
115     constrained = theArray[j]->is_constrained();
116    
117     if(constrained){
118    
119     dummy_plug = theArray[j]->get_constraint();
120     temp_con[c_n_constrained].set_a( dummy_plug->get_a() );
121     temp_con[c_n_constrained].set_b( dummy_plug->get_b() );
122     temp_con[c_n_constrained].set_dsqr( dummy_plug->get_dsqr() );
123    
124     c_n_constrained++;
125     constrained = 0;
126     }
127 mmeineke 377 }
128 mmeineke 423
129    
130 mmeineke 377 }
131    
132     if(c_n_constrained > 0){
133    
134     c_is_constrained = 1;
135     c_constrained_i = new int[c_n_constrained];
136     c_constrained_j = new int[c_n_constrained];
137     c_constrained_dsqr = new double[c_n_constrained];
138 mmeineke 423
139 mmeineke 377 for( int i = 0; i < c_n_constrained; i++){
140    
141     /* add 1 to the index for the fortran arrays. */
142 mmeineke 423
143 mmeineke 377 c_constrained_i[i] = temp_con[i].get_a() + 1;
144     c_constrained_j[i] = temp_con[i].get_b() + 1;
145     c_constrained_dsqr[i] = temp_con[i].get_dsqr();
146     }
147     }
148    
149     delete[] temp_con;
150     }
151    
152    
153     Verlet::~Verlet(){
154    
155     if( c_is_constrained ){
156    
157     delete[] c_constrained_i;
158     delete[] c_constrained_j;
159     delete[] c_constrained_dsqr;
160     }
161    
162     delete[] c_mass;
163     c_mass = 0;
164     }
165    
166    
167     void Verlet::integrate( void ){
168    
169     int i, j; /* loop counters */
170 gezelter 468 int calcPot, calcStress;
171 mmeineke 377
172     double kE;
173    
174     double *Rx = new double[c_natoms];
175     double *Ry = new double[c_natoms];
176     double *Rz = new double[c_natoms];
177    
178     double *Vx = new double[c_natoms];
179     double *Vy = new double[c_natoms];
180     double *Vz = new double[c_natoms];
181    
182     double *Fx = new double[c_natoms];
183     double *Fy = new double[c_natoms];
184     double *Fz = new double[c_natoms];
185    
186     int time;
187    
188     double dt = entry_plug->dt;
189     double runTime = entry_plug->run_time;
190     double sampleTime = entry_plug->sampleTime;
191     double statusTime = entry_plug->statusTime;
192     double thermalTime = entry_plug->thermalTime;
193    
194     int n_loops = (int)( runTime / dt );
195     int sample_n = (int)( sampleTime / dt );
196     int status_n = (int)( statusTime / dt );
197     int vel_n = (int)( thermalTime / dt );
198    
199     Thermo *tStats = new Thermo( entry_plug );
200    
201     StatWriter* e_out = new StatWriter( entry_plug );
202     DumpWriter* dump_out = new DumpWriter( entry_plug );
203    
204     // the first time integrate is called, the forces need to be initialized
205    
206    
207 gezelter 468 myFF->doForces(1,1);
208 mmeineke 377
209     if( entry_plug->setTemp ){
210     tStats->velocitize();
211     }
212    
213     dump_out->writeDump( 0.0 );
214    
215     e_out->writeStat( 0.0 );
216    
217     calcPot = 0;
218    
219 gezelter 475 if (!strcasecmp( entry_plug->ensemble, "NPT")) {
220     calcStress = 1;
221     } else {
222     calcStress = 0;
223     }
224    
225 mmeineke 377 if( c_is_constrained ){
226     for(i = 0; i < n_loops; i++){
227    
228 gezelter 471 if (!strcasecmp( entry_plug->ensemble, "NVT"))
229     myES->NoseHooverNVT( dt , tStats->getKinetic() );
230    
231 mmeineke 377 // fill R, V, and F arrays and RATTLE in fortran
232    
233     for( j=0; j<c_natoms; j++ ){
234    
235     Rx[j] = c_atoms[j]->getX();
236     Ry[j] = c_atoms[j]->getY();
237     Rz[j] = c_atoms[j]->getZ();
238    
239     Vx[j] = c_atoms[j]->get_vx();
240     Vy[j] = c_atoms[j]->get_vy();
241     Vz[j] = c_atoms[j]->get_vz();
242    
243     Fx[j] = c_atoms[j]->getFx();
244     Fy[j] = c_atoms[j]->getFy();
245     Fz[j] = c_atoms[j]->getFz();
246    
247     }
248    
249     v_constrain_a_( dt, c_natoms, c_mass, Rx, Ry, Rz, Vx, Vy, Vz,
250     Fx, Fy, Fz,
251     c_n_constrained, c_constrained_dsqr,
252     c_constrained_i, c_constrained_j,
253     c_box_x, c_box_y, c_box_z );
254    
255     for( j=0; j<c_natoms; j++ ){
256    
257     c_atoms[j]->setX(Rx[j]);
258     c_atoms[j]->setY(Ry[j]);
259     c_atoms[j]->setZ(Rz[j]);
260    
261     c_atoms[j]->set_vx(Vx[j]);
262     c_atoms[j]->set_vy(Vy[j]);
263     c_atoms[j]->set_vz(Vz[j]);
264     }
265    
266     // calculate the forces
267    
268 gezelter 468 myFF->doForces(calcPot,calcStress);
269 mmeineke 377
270     // finish the constrain move ( same as above. )
271    
272     for( j=0; j<c_natoms; j++ ){
273    
274     Rx[j] = c_atoms[j]->getX();
275     Ry[j] = c_atoms[j]->getY();
276     Rz[j] = c_atoms[j]->getZ();
277    
278     Vx[j] = c_atoms[j]->get_vx();
279     Vy[j] = c_atoms[j]->get_vy();
280     Vz[j] = c_atoms[j]->get_vz();
281    
282     Fx[j] = c_atoms[j]->getFx();
283     Fy[j] = c_atoms[j]->getFy();
284     Fz[j] = c_atoms[j]->getFz();
285     }
286    
287 gezelter 471
288 mmeineke 377 v_constrain_b_( dt, c_natoms, c_mass, Rx, Ry, Rz, Vx, Vy, Vz,
289     Fx, Fy, Fz,
290     kE, c_n_constrained, c_constrained_dsqr,
291     c_constrained_i, c_constrained_j,
292     c_box_x, c_box_y, c_box_z );
293    
294     for( j=0; j<c_natoms; j++ ){
295    
296     c_atoms[j]->setX(Rx[j]);
297     c_atoms[j]->setY(Ry[j]);
298     c_atoms[j]->setZ(Rz[j]);
299    
300     c_atoms[j]->set_vx(Vx[j]);
301     c_atoms[j]->set_vy(Vy[j]);
302     c_atoms[j]->set_vz(Vz[j]);
303     }
304    
305 gezelter 471 if (!strcasecmp( entry_plug->ensemble, "NVT"))
306     myES->NoseHooverNVT( dt , tStats->getKinetic() );
307    
308     if (!strcasecmp( entry_plug->ensemble, "NPT") )
309     myES->NoseHooverAndersonNPT( dt,
310     tStats->getKinetic(),
311     tStats->getPressure());
312    
313 mmeineke 377 time = i + 1;
314    
315     if( entry_plug->setTemp ){
316     if( !(time % vel_n) ) tStats->velocitize();
317     }
318     if( !(time % sample_n) ) dump_out->writeDump( time * dt );
319 gezelter 468 if( !((time+1) % status_n) ) {
320     calcPot = 1;
321 gezelter 475 // bitwise masking in case we need it for NPT
322     calcStress = (!strcasecmp(entry_plug->ensemble,"NPT")) && 1;
323 gezelter 468 }
324     if( !(time % status_n) ){
325     e_out->writeStat( time * dt );
326     calcPot = 0;
327 gezelter 475 // bitwise masking in case we need it for NPT
328     calcStress = (!strcasecmp(entry_plug->ensemble,"NPT")) && 0;
329 gezelter 468 }
330 mmeineke 377 }
331     }
332     else{
333     for(i = 0; i < n_loops; i++){
334 gezelter 471
335     if (!strcasecmp( entry_plug->ensemble, "NVT"))
336     myES->NoseHooverNVT( dt , tStats->getKinetic() );
337    
338 mmeineke 377 move_a( dt );
339    
340     // calculate the forces
341    
342 gezelter 468 myFF->doForces(calcPot,calcStress);
343 mmeineke 377
344     // complete the verlet move
345    
346     move_b( dt );
347    
348 gezelter 471 if (!strcasecmp( entry_plug->ensemble, "NVT"))
349     myES->NoseHooverNVT( dt , tStats->getKinetic() );
350    
351     if (!strcasecmp( entry_plug->ensemble, "NPT") )
352     myES->NoseHooverAndersonNPT( dt,
353     tStats->getKinetic(),
354     tStats->getPressure());
355    
356 mmeineke 377 time = i + 1;
357    
358     if( entry_plug->setTemp ){
359     if( !(time % vel_n) ) tStats->velocitize();
360     }
361     if( !(time % sample_n) ) dump_out->writeDump( time * dt );
362 gezelter 468 if( !((time+1) % status_n) ) {
363     calcPot = 1;
364 gezelter 475 // bitwise masking in case we need it for NPT
365     calcStress = (!strcasecmp(entry_plug->ensemble,"NPT")) && 1;
366 gezelter 468 }
367     if( !(time % status_n) ){
368     e_out->writeStat( time * dt );
369     calcPot = 0;
370 gezelter 475 // bitwise masking in case we need it for NPT
371     calcStress = (!strcasecmp(entry_plug->ensemble,"NPT")) && 0;
372 gezelter 468 }
373 mmeineke 377 }
374     }
375    
376     dump_out->writeFinal();
377    
378     delete dump_out;
379     delete e_out;
380    
381     }
382    
383    
384     void Verlet::move_a(double dt){
385    
386     const double e_convert = 4.184e-4; // converts kcal/mol -> amu*A^2/fs^2
387    
388     double qx, qy, qz;
389     double vx, vy, vz;
390     int ma;
391     double h_dt = 0.5 * dt;
392     double h_dt2 = h_dt * dt;
393    
394     for( ma = 0; ma < c_natoms; ma++){
395    
396     qx = c_atoms[ma]->getX() + dt * c_atoms[ma]->get_vx() +
397     h_dt2 * c_atoms[ma]->getFx() * e_convert / c_atoms[ma]->getMass();
398     qy = c_atoms[ma]->getY() + dt * c_atoms[ma]->get_vy() +
399     h_dt2 * c_atoms[ma]->getFy() * e_convert / c_atoms[ma]->getMass();
400     qz = c_atoms[ma]->getZ() + dt * c_atoms[ma]->get_vz() +
401     h_dt2 * c_atoms[ma]->getFz() * e_convert / c_atoms[ma]->getMass();
402    
403     vx = c_atoms[ma]->get_vx() +
404     h_dt * c_atoms[ma]->getFx() * e_convert / c_atoms[ma]->getMass();
405     vy = c_atoms[ma]->get_vy() +
406     h_dt * c_atoms[ma]->getFy() * e_convert / c_atoms[ma]->getMass();
407     vz = c_atoms[ma]->get_vz() +
408     h_dt * c_atoms[ma]->getFz() * e_convert / c_atoms[ma]->getMass();
409    
410     c_atoms[ma]->setX(qx);
411     c_atoms[ma]->setY(qy);
412     c_atoms[ma]->setZ(qz);
413    
414     c_atoms[ma]->set_vx(vx);
415     c_atoms[ma]->set_vy(vy);
416     c_atoms[ma]->set_vz(vz);
417     }
418     }
419    
420     void Verlet::move_b( double dt ){
421    
422     const double e_convert = 4.184e-4; // converts kcal/mol -> amu*A^2/fs^2
423    
424     double vx, vy, vz;
425     int mb;
426     double h_dt = 0.5 * dt;
427    
428    
429     for( mb = 0; mb < c_natoms; mb++){
430    
431     vx = c_atoms[mb]->get_vx() +
432     h_dt * c_atoms[mb]->getFx() * e_convert / c_atoms[mb]->getMass();
433     vy = c_atoms[mb]->get_vy() +
434     h_dt * c_atoms[mb]->getFy() * e_convert / c_atoms[mb]->getMass();
435     vz = c_atoms[mb]->get_vz() +
436     h_dt * c_atoms[mb]->getFz() * e_convert / c_atoms[mb]->getMass();
437    
438     c_atoms[mb]->set_vx(vx);
439     c_atoms[mb]->set_vy(vy);
440     c_atoms[mb]->set_vz(vz);
441     }
442     }