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root/group/trunk/OOPSE/libmdtools/Thermo.cpp
Revision: 445
Committed: Thu Apr 3 19:58:24 2003 UTC (21 years, 3 months ago) by gezelter
File size: 7370 byte(s)
Log Message:
Added NVT file (very broken for now)

File Contents

# Content
1 #include <cmath>
2 #include <iostream>
3 using namespace std;
4
5 #ifdef IS_MPI
6 #include <mpi.h>
7 #include <mpi++.h>
8 #endif //is_mpi
9
10 #include "Thermo.hpp"
11 #include "SRI.hpp"
12 #include "Integrator.hpp"
13 #include "simError.h"
14
15 #ifdef IS_MPI
16 #define __C
17 #include "mpiSimulation.hpp"
18 #endif // is_mpi
19
20
21 #define BASE_SEED 123456789
22
23 Thermo::Thermo( SimInfo* the_entry_plug ) {
24 entry_plug = the_entry_plug;
25 int baseSeed = BASE_SEED;
26
27 gaussStream = new gaussianSPRNG( baseSeed );
28 }
29
30 Thermo::~Thermo(){
31 delete gaussStream;
32 }
33
34 double Thermo::getKinetic(){
35
36 const double e_convert = 4.184E-4; // convert kcal/mol -> (amu A^2)/fs^2
37 double vx2, vy2, vz2;
38 double kinetic, v_sqr;
39 int kl;
40 double jx2, jy2, jz2; // the square of the angular momentums
41
42 DirectionalAtom *dAtom;
43
44 int n_atoms;
45 double kinetic_global;
46 Atom** atoms;
47
48
49 n_atoms = entry_plug->n_atoms;
50 atoms = entry_plug->atoms;
51
52 kinetic = 0.0;
53 kinetic_global = 0.0;
54 for( kl=0; kl < n_atoms; kl++ ){
55
56 vx2 = atoms[kl]->get_vx() * atoms[kl]->get_vx();
57 vy2 = atoms[kl]->get_vy() * atoms[kl]->get_vy();
58 vz2 = atoms[kl]->get_vz() * atoms[kl]->get_vz();
59
60 v_sqr = vx2 + vy2 + vz2;
61 kinetic += atoms[kl]->getMass() * v_sqr;
62
63 if( atoms[kl]->isDirectional() ){
64
65 dAtom = (DirectionalAtom *)atoms[kl];
66
67 jx2 = dAtom->getJx() * dAtom->getJx();
68 jy2 = dAtom->getJy() * dAtom->getJy();
69 jz2 = dAtom->getJz() * dAtom->getJz();
70
71 kinetic += (jx2 / dAtom->getIxx()) + (jy2 / dAtom->getIyy())
72 + (jz2 / dAtom->getIzz());
73 }
74 }
75 #ifdef IS_MPI
76 MPI::COMM_WORLD.Allreduce(&kinetic,&kinetic_global,1,MPI_DOUBLE,MPI_SUM);
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 #ifdef IS_MPI
104 /*
105 std::cerr << "node " << worldRank << ": before LONG RANGE pot = " << entry_plug->lrPot
106 << "; pot_local = " << potential_local
107 << "; pot = " << potential << "\n";
108 */
109 #endif
110
111 // Get total potential for entire system from MPI.
112 #ifdef IS_MPI
113 MPI::COMM_WORLD.Allreduce(&potential_local,&potential,1,MPI_DOUBLE,MPI_SUM);
114 #else
115 potential = potential_local;
116 #endif // is_mpi
117
118 #ifdef IS_MPI
119 /*
120 std::cerr << "node " << worldRank << ": after pot = " << potential << "\n";
121 */
122 #endif
123
124 return potential;
125 }
126
127 double Thermo::getTotalE(){
128
129 double total;
130
131 total = this->getKinetic() + this->getPotential();
132 return total;
133 }
134
135 double Thermo::getTemperature(){
136
137 const double kb = 1.9872179E-3; // boltzman's constant in kcal/(mol K)
138 double temperature;
139 int ndf_local, ndf;
140
141 ndf_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented
142 - entry_plug->n_constraints;
143
144 #ifdef IS_MPI
145 MPI::COMM_WORLD.Allreduce(&ndf_local,&ndf,1,MPI_INT,MPI_SUM);
146 #else
147 ndf = ndf_local;
148 #endif
149
150 ndf = ndf - 3;
151
152 temperature = ( 2.0 * this->getKinetic() ) / ( ndf * kb );
153 return temperature;
154 }
155
156 double Thermo::getPressure(){
157 // returns pressure in units amu*fs^-2*Ang^-1
158 // routine derived via viral theorem description in:
159 // Paci, E. and Marchi, M. J.Phys.Chem. 1996, 100, 4314-4322
160
161 return 0.0;
162 }
163
164 void Thermo::velocitize() {
165
166 double x,y;
167 double vx, vy, vz;
168 double jx, jy, jz;
169 int i, vr, vd; // velocity randomizer loop counters
170 double vdrift[3];
171 double vbar;
172 const double kb = 8.31451e-7; // kb in amu, angstroms, fs, etc.
173 double av2;
174 double kebar;
175 int ndf, ndf_local; // number of degrees of freedom
176 int ndfRaw, ndfRaw_local; // the raw number of degrees of freedom
177 int n_atoms;
178 Atom** atoms;
179 DirectionalAtom* dAtom;
180 double temperature;
181 int n_oriented;
182 int n_constraints;
183
184 atoms = entry_plug->atoms;
185 n_atoms = entry_plug->n_atoms;
186 temperature = entry_plug->target_temp;
187 n_oriented = entry_plug->n_oriented;
188 n_constraints = entry_plug->n_constraints;
189
190 // Raw degrees of freedom that we have to set
191 ndfRaw_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented;
192
193 // Degrees of freedom that can contain kinetic energy
194 ndf_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented
195 - entry_plug->n_constraints;
196
197 #ifdef IS_MPI
198 MPI::COMM_WORLD.Allreduce(&ndf_local,&ndf,1,MPI_INT,MPI_SUM);
199 MPI::COMM_WORLD.Allreduce(&ndfRaw_local,&ndfRaw,1,MPI_INT,MPI_SUM);
200 #else
201 ndfRaw = ndfRaw_local;
202 ndf = ndf_local;
203 #endif
204 ndf = ndf - 3;
205
206 kebar = kb * temperature * (double)ndf / ( 2.0 * (double)ndfRaw );
207
208 for(vr = 0; vr < n_atoms; vr++){
209
210 // uses equipartition theory to solve for vbar in angstrom/fs
211
212 av2 = 2.0 * kebar / atoms[vr]->getMass();
213 vbar = sqrt( av2 );
214
215 // vbar = sqrt( 8.31451e-7 * temperature / atoms[vr]->getMass() );
216
217 // picks random velocities from a gaussian distribution
218 // centered on vbar
219
220 vx = vbar * gaussStream->getGaussian();
221 vy = vbar * gaussStream->getGaussian();
222 vz = vbar * gaussStream->getGaussian();
223
224 atoms[vr]->set_vx( vx );
225 atoms[vr]->set_vy( vy );
226 atoms[vr]->set_vz( vz );
227 }
228
229 // Get the Center of Mass drift velocity.
230
231 getCOMVel(vdrift);
232
233 // Corrects for the center of mass drift.
234 // sums all the momentum and divides by total mass.
235
236 for(vd = 0; vd < n_atoms; vd++){
237
238 vx = atoms[vd]->get_vx();
239 vy = atoms[vd]->get_vy();
240 vz = atoms[vd]->get_vz();
241
242 vx -= vdrift[0];
243 vy -= vdrift[1];
244 vz -= vdrift[2];
245
246 atoms[vd]->set_vx(vx);
247 atoms[vd]->set_vy(vy);
248 atoms[vd]->set_vz(vz);
249 }
250 if( n_oriented ){
251
252 for( i=0; i<n_atoms; i++ ){
253
254 if( atoms[i]->isDirectional() ){
255
256 dAtom = (DirectionalAtom *)atoms[i];
257
258 vbar = sqrt( 2.0 * kebar * dAtom->getIxx() );
259 jx = vbar * gaussStream->getGaussian();
260
261 vbar = sqrt( 2.0 * kebar * dAtom->getIyy() );
262 jy = vbar * gaussStream->getGaussian();
263
264 vbar = sqrt( 2.0 * kebar * dAtom->getIzz() );
265 jz = vbar * gaussStream->getGaussian();
266
267 dAtom->setJx( jx );
268 dAtom->setJy( jy );
269 dAtom->setJz( jz );
270 }
271 }
272 }
273 }
274
275 void Thermo::getCOMVel(double vdrift[3]){
276
277 double mtot, mtot_local;
278 double vdrift_local[3];
279 int vd, n_atoms;
280 Atom** atoms;
281
282 // We are very careless here with the distinction between n_atoms and n_local
283 // We should really fix this before someone pokes an eye out.
284
285 n_atoms = entry_plug->n_atoms;
286 atoms = entry_plug->atoms;
287
288 mtot_local = 0.0;
289 vdrift_local[0] = 0.0;
290 vdrift_local[1] = 0.0;
291 vdrift_local[2] = 0.0;
292
293 for(vd = 0; vd < n_atoms; vd++){
294
295 vdrift_local[0] += atoms[vd]->get_vx() * atoms[vd]->getMass();
296 vdrift_local[1] += atoms[vd]->get_vy() * atoms[vd]->getMass();
297 vdrift_local[2] += atoms[vd]->get_vz() * atoms[vd]->getMass();
298
299 mtot_local += atoms[vd]->getMass();
300 }
301
302 #ifdef IS_MPI
303 MPI::COMM_WORLD.Allreduce(&mtot_local,&mtot,1,MPI_DOUBLE,MPI_SUM);
304 MPI::COMM_WORLD.Allreduce(vdrift_local,vdrift,3,MPI_DOUBLE,MPI_SUM);
305 #else
306 mtot = mtot_local;
307 for(vd = 0; vd < 3; vd++) {
308 vdrift[vd] = vdrift_local[vd];
309 }
310 #endif
311
312 for (vd = 0; vd < 3; vd++) {
313 vdrift[vd] = vdrift[vd] / mtot;
314 }
315
316 }
317