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root/group/trunk/OOPSE/libmdtools/ExtendedSystem.cpp
Revision: 488
Committed: Thu Apr 10 16:35:31 2003 UTC (21 years, 3 months ago) by gezelter
File size: 12135 byte(s)
Log Message:
Working on ConstantStress

File Contents

# User Rev Content
1 gezelter 453 #include <math.h>
2 gezelter 454 #include "Atom.hpp"
3     #include "Molecule.hpp"
4     #include "SimInfo.hpp"
5     #include "Thermo.hpp"
6     #include "ExtendedSystem.hpp"
7 gezelter 481 #include "simError.h"
8 gezelter 453
9 gezelter 466 ExtendedSystem::ExtendedSystem( SimInfo* the_entry_plug ) {
10 gezelter 453
11     // get what information we need from the SimInfo object
12    
13 gezelter 466 entry_plug = the_entry_plug;
14 gezelter 457 zeta = 0.0;
15     epsilonDot = 0.0;
16 gezelter 488 epsilonDotX = 0.0;
17     epsilonDotY = 0.0;
18     epsilonDotZ = 0.0;
19 gezelter 481 have_tau_thermostat = 0;
20     have_tau_barostat = 0;
21     have_target_temp = 0;
22     have_target_pressure = 0;
23     have_qmass = 0;
24    
25 gezelter 453 }
26    
27 gezelter 457 void ExtendedSystem::NoseHooverNVT( double dt, double ke ){
28 gezelter 453
29     // Basic thermostating via Hoover, Phys.Rev.A, 1985, Vol. 31 (5) 1695-1697
30    
31 gezelter 454 int i;
32 gezelter 457 double NkBT, zetaScale, ke_temp;
33 gezelter 454 double vx, vy, vz, jx, jy, jz;
34 gezelter 457 const double kB = 8.31451e-7; // boltzmann constant in amu*Ang^2*fs^-2/K
35     const double e_convert = 4.184e-4; // to convert ke from kcal/mol to
36     // amu*Ang^2*fs^-2/K
37 gezelter 458 DirectionalAtom* dAtom;
38    
39 gezelter 481 if (this->NVTready()) {
40 gezelter 453
41 gezelter 481 atoms = entry_plug->atoms;
42 gezelter 454
43 gezelter 481 ke_temp = ke * e_convert;
44     NkBT = (double)entry_plug->ndf * kB * targetTemp;
45 gezelter 454
46 gezelter 481 // advance the zeta term to zeta(t + dt) - zeta is 0.0d0 on config. readin
47     // qmass is set in the parameter file
48    
49     zeta += dt * ( (ke_temp*2.0 - NkBT) / qmass );
50    
51     zetaScale = zeta * dt;
52    
53 gezelter 484 //std::cerr << "zetaScale = " << zetaScale << "\n";
54 gezelter 481
55     // perform thermostat scaling on linear velocities and angular momentum
56     for(i = 0; i < entry_plug->n_atoms; i++){
57 gezelter 454
58 gezelter 481 vx = atoms[i]->get_vx();
59     vy = atoms[i]->get_vy();
60     vz = atoms[i]->get_vz();
61    
62     atoms[i]->set_vx(vx * (1.0 - zetaScale));
63     atoms[i]->set_vy(vy * (1.0 - zetaScale));
64     atoms[i]->set_vz(vz * (1.0 - zetaScale));
65     }
66     if( entry_plug->n_oriented ){
67    
68     for( i=0; i < entry_plug->n_atoms; i++ ){
69 gezelter 454
70 gezelter 481 if( atoms[i]->isDirectional() ){
71    
72     dAtom = (DirectionalAtom *)atoms[i];
73    
74     jx = dAtom->getJx();
75     jy = dAtom->getJy();
76     jz = dAtom->getJz();
77    
78     dAtom->setJx(jx * (1.0 - zetaScale));
79     dAtom->setJy(jy * (1.0 - zetaScale));
80     dAtom->setJz(jz * (1.0 - zetaScale));
81     }
82     }
83     }
84 gezelter 454 }
85 gezelter 453 }
86    
87    
88 gezelter 457 void ExtendedSystem::NoseHooverAndersonNPT( double dt,
89     double ke,
90 gezelter 483 double p_tensor[9] ) {
91 gezelter 453
92     // Basic barostating via Hoover, Phys.Rev.A, 1985, Vol. 31 (5) 1695-1697
93     // Hoover, Phys.Rev.A, 1986, Vol.34 (3) 2499-2500
94    
95 gezelter 457 double oldBox[3];
96     double newBox[3];
97     const double kB = 8.31451e-7; // boltzmann constant in amu*Ang^2*fs^-2/K
98     const double p_units = 6.10192996e-9; // converts atm to amu*fs^-2*Ang^-1
99     const double e_convert = 4.184e-4; // to convert ke from kcal/mol to
100     // amu*Ang^2*fs^-2/K
101 gezelter 453
102 gezelter 474 int i;
103 gezelter 458 double p_ext, zetaScale, epsilonScale, scale, NkBT, ke_temp;
104     double volume, p_mol;
105     double vx, vy, vz, jx, jy, jz;
106     DirectionalAtom* dAtom;
107 gezelter 453
108 gezelter 481 if (this->NPTready()) {
109     atoms = entry_plug->atoms;
110 gezelter 454
111 gezelter 481 p_ext = targetPressure * p_units;
112 gezelter 483 p_mol = (p_tensor[0] + p_tensor[4] + p_tensor[8])/3.0;
113    
114 gezelter 481 entry_plug->getBox(oldBox);
115     volume = oldBox[0]*oldBox[1]*oldBox[2];
116 gezelter 454
117 gezelter 481 ke_temp = ke * e_convert;
118     NkBT = (double)entry_plug->ndf * kB * targetTemp;
119    
120 gezelter 483 // propagate the strain rate
121 gezelter 481
122     epsilonDot += dt * ((p_mol - p_ext) * volume /
123     (tauBarostat*tauBarostat * kB * targetTemp) );
124    
125     // determine the change in cell volume
126     scale = pow( (1.0 + dt * 3.0 * epsilonDot), (1.0 / 3.0));
127 gezelter 484 //std::cerr << "pmol = " << p_mol << " p_ext = " << p_ext << " scale = " << scale << "\n";
128 gezelter 481
129     newBox[0] = oldBox[0] * scale;
130     newBox[1] = oldBox[1] * scale;
131     newBox[2] = oldBox[2] * scale;
132     volume = newBox[0]*newBox[1]*newBox[2];
133    
134     entry_plug->setBox(newBox);
135    
136     // perform affine transform to update positions with volume fluctuations
137     this->AffineTransform( oldBox, newBox );
138    
139     epsilonScale = epsilonDot * dt;
140    
141     // advance the zeta term to zeta(t + dt) - zeta is 0.0d0 on config. readin
142     // qmass is set in the parameter file
143    
144     zeta += dt * ( (ke_temp*2.0 - NkBT) / qmass );
145     zetaScale = zeta * dt;
146    
147 gezelter 484 //std::cerr << "zetaScale = " << zetaScale << " epsilonScale = " << epsilonScale << "\n";
148 gezelter 481
149     // apply barostating and thermostating to velocities and angular momenta
150     for(i = 0; i < entry_plug->n_atoms; i++){
151 gezelter 454
152 gezelter 481 vx = atoms[i]->get_vx();
153     vy = atoms[i]->get_vy();
154     vz = atoms[i]->get_vz();
155    
156     atoms[i]->set_vx(vx * (1.0 - zetaScale - epsilonScale));
157     atoms[i]->set_vy(vy * (1.0 - zetaScale - epsilonScale));
158     atoms[i]->set_vz(vz * (1.0 - zetaScale - epsilonScale));
159     }
160     if( entry_plug->n_oriented ){
161    
162     for( i=0; i < entry_plug->n_atoms; i++ ){
163 gezelter 454
164 gezelter 481 if( atoms[i]->isDirectional() ){
165    
166     dAtom = (DirectionalAtom *)atoms[i];
167    
168     jx = dAtom->getJx();
169     jy = dAtom->getJy();
170     jz = dAtom->getJz();
171    
172     dAtom->setJx( jx * (1.0 - zetaScale));
173     dAtom->setJy( jy * (1.0 - zetaScale));
174     dAtom->setJz( jz * (1.0 - zetaScale));
175     }
176     }
177 gezelter 488 }
178     }
179     }
180    
181    
182     void ExtendedSystem::ConstantStress( double dt,
183     double ke,
184     double p_tensor[9] ) {
185    
186     double oldBox[3];
187     double newBox[3];
188     const double kB = 8.31451e-7; // boltzmann constant in amu*Ang^2*fs^-2/K
189     const double p_units = 6.10192996e-9; // converts atm to amu*fs^-2*Ang^-1
190     const double e_convert = 4.184e-4; // to convert ke from kcal/mol to
191     // amu*Ang^2*fs^-2/K
192    
193     int i;
194     double p_ext, zetaScale, epsilonScale, scale, NkBT, ke_temp;
195     double pX_ext, pY_ext, pZ_ext;
196     double volume, p_mol;
197     double vx, vy, vz, jx, jy, jz;
198     DirectionalAtom* dAtom;
199    
200     if (this->NPTready()) {
201     atoms = entry_plug->atoms;
202    
203     p_ext = targetPressure * p_units;
204    
205     pX_ext = p_ext / 3.0;
206     pY_ext = p_ext / 3.0;
207     pZ_ext = p_ext / 3.0;
208    
209     entry_plug->getBox(oldBox);
210     volume = oldBox[0]*oldBox[1]*oldBox[2];
211    
212     ke_temp = ke * e_convert;
213     NkBT = (double)entry_plug->ndf * kB * targetTemp;
214    
215     // propagate the strain rate
216    
217     epsilonDotX += dt * ((p_tensor[0] - pX_ext) * volume /
218     (tauBarostat*tauBarostat * kB * targetTemp) );
219     epsilonDotY += dt * ((p_tensor[4] - pY_ext) * volume /
220     (tauBarostat*tauBarostat * kB * targetTemp) );
221     epsilonDotZ += dt * ((p_tensor[8] - pZ_ext) * volume /
222     (tauBarostat*tauBarostat * kB * targetTemp) );
223    
224     // determine the change in cell volume
225    
226     //scale = pow( (1.0 + dt * 3.0 * (epsilonDot), (1.0 / 3.0));
227     //std::cerr << "pmol = " << p_mol << " p_ext = " << p_ext << " scale = " << scale << "\n";
228    
229     newBox[0] = oldBox[0] * scale;
230     newBox[1] = oldBox[1] * scale;
231     newBox[2] = oldBox[2] * scale;
232     volume = newBox[0]*newBox[1]*newBox[2];
233    
234     entry_plug->setBox(newBox);
235    
236     // perform affine transform to update positions with volume fluctuations
237     this->AffineTransform( oldBox, newBox );
238    
239     epsilonScale = epsilonDot * dt;
240    
241     // advance the zeta term to zeta(t + dt) - zeta is 0.0d0 on config. readin
242     // qmass is set in the parameter file
243    
244     zeta += dt * ( (ke_temp*2.0 - NkBT) / qmass );
245     zetaScale = zeta * dt;
246    
247     //std::cerr << "zetaScale = " << zetaScale << " epsilonScale = " << epsilonScale << "\n";
248    
249     // apply barostating and thermostating to velocities and angular momenta
250     for(i = 0; i < entry_plug->n_atoms; i++){
251    
252     vx = atoms[i]->get_vx();
253     vy = atoms[i]->get_vy();
254     vz = atoms[i]->get_vz();
255    
256     atoms[i]->set_vx(vx * (1.0 - zetaScale - epsilonScale));
257     atoms[i]->set_vy(vy * (1.0 - zetaScale - epsilonScale));
258     atoms[i]->set_vz(vz * (1.0 - zetaScale - epsilonScale));
259     }
260     if( entry_plug->n_oriented ){
261    
262     for( i=0; i < entry_plug->n_atoms; i++ ){
263    
264     if( atoms[i]->isDirectional() ){
265    
266     dAtom = (DirectionalAtom *)atoms[i];
267    
268     jx = dAtom->getJx();
269     jy = dAtom->getJy();
270     jz = dAtom->getJz();
271    
272     dAtom->setJx( jx * (1.0 - zetaScale));
273     dAtom->setJy( jy * (1.0 - zetaScale));
274     dAtom->setJz( jz * (1.0 - zetaScale));
275     }
276     }
277 gezelter 481 }
278 gezelter 454 }
279 gezelter 453 }
280    
281 gezelter 457 void ExtendedSystem::AffineTransform( double oldBox[3], double newBox[3] ){
282 gezelter 453
283     int i;
284 gezelter 457 double r[3];
285     double boxNum[3];
286     double percentScale[3];
287 gezelter 476 double delta[3];
288 gezelter 457 double rxi, ryi, rzi;
289 gezelter 474
290     molecules = entry_plug->molecules;
291 gezelter 453
292     // first determine the scaling factor from the box size change
293 gezelter 457 percentScale[0] = (newBox[0] - oldBox[0]) / oldBox[0];
294     percentScale[1] = (newBox[1] - oldBox[1]) / oldBox[1];
295     percentScale[2] = (newBox[2] - oldBox[2]) / oldBox[2];
296 gezelter 453
297 gezelter 474 for (i=0; i < entry_plug->n_mol; i++) {
298 gezelter 453
299 gezelter 458 molecules[i].getCOM(r);
300 gezelter 475
301 gezelter 457 // find the minimum image coordinates of the molecular centers of mass:
302 gezelter 453
303 gezelter 457 boxNum[0] = oldBox[0] * copysign(1.0,r[0]) *
304     (double)(int)(fabs(r[0]/oldBox[0]) + 0.5);
305 gezelter 453
306 gezelter 457 boxNum[1] = oldBox[1] * copysign(1.0,r[1]) *
307     (double)(int)(fabs(r[1]/oldBox[1]) + 0.5);
308 gezelter 453
309 gezelter 457 boxNum[2] = oldBox[2] * copysign(1.0,r[2]) *
310     (double)(int)(fabs(r[2]/oldBox[2]) + 0.5);
311 gezelter 453
312 gezelter 457 rxi = r[0] - boxNum[0];
313     ryi = r[1] - boxNum[1];
314     rzi = r[2] - boxNum[2];
315    
316 gezelter 453 // update the minimum image coordinates using the scaling factor
317 gezelter 457 rxi += rxi*percentScale[0];
318     ryi += ryi*percentScale[1];
319     rzi += rzi*percentScale[2];
320 gezelter 453
321 gezelter 476 delta[0] = r[0] - (rxi + boxNum[0]);
322     delta[1] = r[1] - (ryi + boxNum[1]);
323     delta[2] = r[2] - (rzi + boxNum[2]);
324 gezelter 457
325 gezelter 476 molecules[i].moveCOM(delta);
326 gezelter 453 }
327     }
328 gezelter 481
329     short int ExtendedSystem::NVTready() {
330     const double kB = 8.31451e-7; // boltzmann constant in amu*Ang^2*fs^-2/K
331     double NkBT;
332    
333     if (!have_target_temp) {
334     sprintf( painCave.errMsg,
335     "ExtendedSystem error: You can't use NVT without a targetTemp!\n"
336     );
337     painCave.isFatal = 1;
338     simError();
339     return -1;
340     }
341    
342     if (!have_qmass) {
343     if (have_tau_thermostat) {
344    
345     NkBT = (double)entry_plug->ndf * kB * targetTemp;
346     std::cerr << "Setting qMass = " << tauThermostat * NkBT << "\n";
347     this->setQmass(tauThermostat * NkBT);
348    
349     } else {
350     sprintf( painCave.errMsg,
351     "ExtendedSystem error: If you use the constant temperature\n"
352     " ensemble, you must set either tauThermostat or qMass.\n");
353     painCave.isFatal = 1;
354     simError();
355     }
356     }
357    
358 gezelter 483 return 1;
359 gezelter 481 }
360    
361     short int ExtendedSystem::NPTready() {
362     const double kB = 8.31451e-7; // boltzmann constant in amu*Ang^2*fs^-2/K
363     double NkBT;
364    
365     if (!have_target_temp) {
366     sprintf( painCave.errMsg,
367     "ExtendedSystem error: You can't use NPT without a targetTemp!\n"
368     );
369     painCave.isFatal = 1;
370     simError();
371     return -1;
372     }
373    
374     if (!have_target_pressure) {
375     sprintf( painCave.errMsg,
376     "ExtendedSystem error: You can't use NPT without a targetPressure!\n"
377     );
378     painCave.isFatal = 1;
379     simError();
380     return -1;
381     }
382    
383     if (!have_tau_barostat) {
384     sprintf( painCave.errMsg,
385     "ExtendedSystem error: If you use the NPT\n"
386     " ensemble, you must set tauBarostat.\n");
387     painCave.isFatal = 1;
388     simError();
389     }
390    
391     if (!have_qmass) {
392     if (have_tau_thermostat) {
393    
394     NkBT = (double)entry_plug->ndf * kB * targetTemp;
395     std::cerr << "Setting qMass = " << tauThermostat * NkBT << "\n";
396     this->setQmass(tauThermostat * NkBT);
397    
398     } else {
399     sprintf( painCave.errMsg,
400     "ExtendedSystem error: If you use the NPT\n"
401     " ensemble, you must set either tauThermostat or qMass.\n");
402     painCave.isFatal = 1;
403     simError();
404     }
405     }
406 gezelter 483 return 1;
407 gezelter 481 }
408