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root/group/trunk/OOPSE/libmdtools/Thermo.cpp
Revision: 572
Committed: Wed Jul 2 21:26:55 2003 UTC (21 years ago) by mmeineke
File size: 8389 byte(s)
Log Message:
fixed the bugs introduced by switching the periodic box to a matrix

File Contents

# Content
1 #include <cmath>
2 #include <iostream>
3 using namespace std;
4
5 #ifdef IS_MPI
6 #include <mpi.h>
7 #endif //is_mpi
8
9 #include "Thermo.hpp"
10 #include "SRI.hpp"
11 #include "Integrator.hpp"
12 #include "simError.h"
13
14 #ifdef IS_MPI
15 #define __C
16 #include "mpiSimulation.hpp"
17 #endif // is_mpi
18
19
20 #define BASE_SEED 123456789
21
22 Thermo::Thermo( SimInfo* the_entry_plug ) {
23 entry_plug = the_entry_plug;
24 int baseSeed = BASE_SEED;
25
26 gaussStream = new gaussianSPRNG( baseSeed );
27 }
28
29 Thermo::~Thermo(){
30 delete gaussStream;
31 }
32
33 double Thermo::getKinetic(){
34
35 const double e_convert = 4.184E-4; // convert kcal/mol -> (amu A^2)/fs^2
36 double vx2, vy2, vz2;
37 double kinetic, v_sqr;
38 int kl;
39 double jx2, jy2, jz2; // the square of the angular momentums
40
41 DirectionalAtom *dAtom;
42
43 int n_atoms;
44 double kinetic_global;
45 Atom** atoms;
46
47
48 n_atoms = entry_plug->n_atoms;
49 atoms = entry_plug->atoms;
50
51 kinetic = 0.0;
52 kinetic_global = 0.0;
53 for( kl=0; kl < n_atoms; kl++ ){
54
55 vx2 = atoms[kl]->get_vx() * atoms[kl]->get_vx();
56 vy2 = atoms[kl]->get_vy() * atoms[kl]->get_vy();
57 vz2 = atoms[kl]->get_vz() * atoms[kl]->get_vz();
58
59 v_sqr = vx2 + vy2 + vz2;
60 kinetic += atoms[kl]->getMass() * v_sqr;
61
62 if( atoms[kl]->isDirectional() ){
63
64 dAtom = (DirectionalAtom *)atoms[kl];
65
66 jx2 = dAtom->getJx() * dAtom->getJx();
67 jy2 = dAtom->getJy() * dAtom->getJy();
68 jz2 = dAtom->getJz() * dAtom->getJz();
69
70 kinetic += (jx2 / dAtom->getIxx()) + (jy2 / dAtom->getIyy())
71 + (jz2 / dAtom->getIzz());
72 }
73 }
74 #ifdef IS_MPI
75 MPI_Allreduce(&kinetic,&kinetic_global,1,MPI_DOUBLE,
76 MPI_SUM, MPI_COMM_WORLD);
77 kinetic = kinetic_global;
78 #endif //is_mpi
79
80 kinetic = kinetic * 0.5 / e_convert;
81
82 return kinetic;
83 }
84
85 double Thermo::getPotential(){
86
87 double potential_local;
88 double potential;
89 int el, nSRI;
90 Molecule* molecules;
91
92 molecules = entry_plug->molecules;
93 nSRI = entry_plug->n_SRI;
94
95 potential_local = 0.0;
96 potential = 0.0;
97 potential_local += entry_plug->lrPot;
98
99 for( el=0; el<entry_plug->n_mol; el++ ){
100 potential_local += molecules[el].getPotential();
101 }
102
103 // Get total potential for entire system from MPI.
104 #ifdef IS_MPI
105 MPI_Allreduce(&potential_local,&potential,1,MPI_DOUBLE,
106 MPI_SUM, MPI_COMM_WORLD);
107 #else
108 potential = potential_local;
109 #endif // is_mpi
110
111 #ifdef IS_MPI
112 /*
113 std::cerr << "node " << worldRank << ": after pot = " << potential << "\n";
114 */
115 #endif
116
117 return potential;
118 }
119
120 double Thermo::getTotalE(){
121
122 double total;
123
124 total = this->getKinetic() + this->getPotential();
125 return total;
126 }
127
128 double Thermo::getTemperature(){
129
130 const double kb = 1.9872179E-3; // boltzman's constant in kcal/(mol K)
131 double temperature;
132
133 temperature = ( 2.0 * this->getKinetic() ) / ((double)entry_plug->ndf * kb );
134 return temperature;
135 }
136
137 double Thermo::getEnthalpy() {
138
139 const double e_convert = 4.184E-4; // convert kcal/mol -> (amu A^2)/fs^2
140 double u, p, v;
141 double press[9];
142
143 u = this->getTotalE();
144
145 this->getPressureTensor(press);
146 p = (press[0] + press[4] + press[8]) / 3.0;
147
148 v = this->getVolume();
149
150 return (u + (p*v)/e_convert);
151 }
152
153 double Thermo::getVolume() {
154 return entry_plug->boxVol;
155 }
156
157 double Thermo::getPressure() {
158 // returns the pressure in units of atm
159 // Relies on the calculation of the full molecular pressure tensor
160
161 const double p_convert = 1.63882576e8;
162 double press[9];
163 double pressure;
164
165 this->getPressureTensor(press);
166
167 pressure = p_convert * (press[0] + press[4] + press[8]) / 3.0;
168
169 return pressure;
170 }
171
172
173 void Thermo::getPressureTensor(double press[9]){
174 // returns pressure tensor in units amu*fs^-2*Ang^-1
175 // routine derived via viral theorem description in:
176 // Paci, E. and Marchi, M. J.Phys.Chem. 1996, 100, 4314-4322
177
178 const double e_convert = 4.184e-4;
179
180 double molmass, volume;
181 double vcom[3];
182 double p_local[9], p_global[9];
183 double theBox[3];
184 //double* tau;
185 int i, nMols;
186 Molecule* molecules;
187
188 nMols = entry_plug->n_mol;
189 molecules = entry_plug->molecules;
190 //tau = entry_plug->tau;
191
192 // use velocities of molecular centers of mass and molecular masses:
193 for (i=0; i < 9; i++) {
194 p_local[i] = 0.0;
195 p_global[i] = 0.0;
196 }
197
198 for (i=0; i < nMols; i++) {
199 molmass = molecules[i].getCOMvel(vcom);
200
201 p_local[0] += molmass * (vcom[0] * vcom[0]);
202 p_local[1] += molmass * (vcom[0] * vcom[1]);
203 p_local[2] += molmass * (vcom[0] * vcom[2]);
204 p_local[3] += molmass * (vcom[1] * vcom[0]);
205 p_local[4] += molmass * (vcom[1] * vcom[1]);
206 p_local[5] += molmass * (vcom[1] * vcom[2]);
207 p_local[6] += molmass * (vcom[2] * vcom[0]);
208 p_local[7] += molmass * (vcom[2] * vcom[1]);
209 p_local[8] += molmass * (vcom[2] * vcom[2]);
210 }
211
212 // Get total for entire system from MPI.
213
214 #ifdef IS_MPI
215 MPI_Allreduce(p_local,p_global,9,MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
216 #else
217 for (i=0; i<9; i++) {
218 p_global[i] = p_local[i];
219 }
220 #endif // is_mpi
221
222 volume = entry_plug->boxVol;
223
224 for(i=0; i<9; i++) {
225 press[i] = (p_global[i] - entry_plug->tau[i]*e_convert) / volume;
226 }
227 }
228
229 void Thermo::velocitize() {
230
231 double x,y;
232 double vx, vy, vz;
233 double jx, jy, jz;
234 int i, vr, vd; // velocity randomizer loop counters
235 double vdrift[3];
236 double vbar;
237 const double kb = 8.31451e-7; // kb in amu, angstroms, fs, etc.
238 double av2;
239 double kebar;
240 int n_atoms;
241 Atom** atoms;
242 DirectionalAtom* dAtom;
243 double temperature;
244 int n_oriented;
245 int n_constraints;
246
247 atoms = entry_plug->atoms;
248 n_atoms = entry_plug->n_atoms;
249 temperature = entry_plug->target_temp;
250 n_oriented = entry_plug->n_oriented;
251 n_constraints = entry_plug->n_constraints;
252
253 kebar = kb * temperature * (double)entry_plug->ndf /
254 ( 2.0 * (double)entry_plug->ndfRaw );
255
256 for(vr = 0; vr < n_atoms; vr++){
257
258 // uses equipartition theory to solve for vbar in angstrom/fs
259
260 av2 = 2.0 * kebar / atoms[vr]->getMass();
261 vbar = sqrt( av2 );
262
263 // vbar = sqrt( 8.31451e-7 * temperature / atoms[vr]->getMass() );
264
265 // picks random velocities from a gaussian distribution
266 // centered on vbar
267
268 vx = vbar * gaussStream->getGaussian();
269 vy = vbar * gaussStream->getGaussian();
270 vz = vbar * gaussStream->getGaussian();
271
272 atoms[vr]->set_vx( vx );
273 atoms[vr]->set_vy( vy );
274 atoms[vr]->set_vz( vz );
275 }
276
277 // Get the Center of Mass drift velocity.
278
279 getCOMVel(vdrift);
280
281 // Corrects for the center of mass drift.
282 // sums all the momentum and divides by total mass.
283
284 for(vd = 0; vd < n_atoms; vd++){
285
286 vx = atoms[vd]->get_vx();
287 vy = atoms[vd]->get_vy();
288 vz = atoms[vd]->get_vz();
289
290 vx -= vdrift[0];
291 vy -= vdrift[1];
292 vz -= vdrift[2];
293
294 atoms[vd]->set_vx(vx);
295 atoms[vd]->set_vy(vy);
296 atoms[vd]->set_vz(vz);
297 }
298 if( n_oriented ){
299
300 for( i=0; i<n_atoms; i++ ){
301
302 if( atoms[i]->isDirectional() ){
303
304 dAtom = (DirectionalAtom *)atoms[i];
305
306 vbar = sqrt( 2.0 * kebar * dAtom->getIxx() );
307 jx = vbar * gaussStream->getGaussian();
308
309 vbar = sqrt( 2.0 * kebar * dAtom->getIyy() );
310 jy = vbar * gaussStream->getGaussian();
311
312 vbar = sqrt( 2.0 * kebar * dAtom->getIzz() );
313 jz = vbar * gaussStream->getGaussian();
314
315 dAtom->setJx( jx );
316 dAtom->setJy( jy );
317 dAtom->setJz( jz );
318 }
319 }
320 }
321 }
322
323 void Thermo::getCOMVel(double vdrift[3]){
324
325 double mtot, mtot_local;
326 double vdrift_local[3];
327 int vd, n_atoms;
328 Atom** atoms;
329
330 // We are very careless here with the distinction between n_atoms and n_local
331 // We should really fix this before someone pokes an eye out.
332
333 n_atoms = entry_plug->n_atoms;
334 atoms = entry_plug->atoms;
335
336 mtot_local = 0.0;
337 vdrift_local[0] = 0.0;
338 vdrift_local[1] = 0.0;
339 vdrift_local[2] = 0.0;
340
341 for(vd = 0; vd < n_atoms; vd++){
342
343 vdrift_local[0] += atoms[vd]->get_vx() * atoms[vd]->getMass();
344 vdrift_local[1] += atoms[vd]->get_vy() * atoms[vd]->getMass();
345 vdrift_local[2] += atoms[vd]->get_vz() * atoms[vd]->getMass();
346
347 mtot_local += atoms[vd]->getMass();
348 }
349
350 #ifdef IS_MPI
351 MPI_Allreduce(&mtot_local,&mtot,1,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
352 MPI_Allreduce(vdrift_local,vdrift,3,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
353 #else
354 mtot = mtot_local;
355 for(vd = 0; vd < 3; vd++) {
356 vdrift[vd] = vdrift_local[vd];
357 }
358 #endif
359
360 for (vd = 0; vd < 3; vd++) {
361 vdrift[vd] = vdrift[vd] / mtot;
362 }
363
364 }
365