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root/group/trunk/OOPSE/libmdtools/Thermo.cpp
Revision: 454
Committed: Fri Apr 4 01:57:11 2003 UTC (21 years, 3 months ago) by gezelter
File size: 7086 byte(s)
Log Message:
changes for extended system code

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 int Thermo::getNDF(){
129 int ndf_local, ndf;
130
131 ndf_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented
132 - entry_plug->n_constraints;
133
134 #ifdef IS_MPI
135 MPI_Allreduce(&ndf_local,&ndf,1,MPI_INT,MPI_SUM, MPI_COMM_WORLD);
136 #else
137 ndf = ndf_local;
138 #endif
139
140 ndf = ndf - 3;
141
142 return ndf;
143 }
144
145 int Thermo::getNDFraw() {
146 int ndfRaw_local, ndfRaw;
147
148 // Raw degrees of freedom that we have to set
149 ndfRaw_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented;
150
151 #ifdef IS_MPI
152 MPI_Allreduce(&ndfRaw_local,&ndfRaw,1,MPI_INT,MPI_SUM, MPI_COMM_WORLD);
153 #else
154 ndfRaw = ndfRaw_local;
155 #endif
156
157 return ndfRaw;
158 }
159
160
161 double Thermo::getTemperature(){
162
163 const double kb = 1.9872179E-3; // boltzman's constant in kcal/(mol K)
164 double temperature;
165
166 temperature = ( 2.0 * this->getKinetic() ) / ( (double)this->getNDF() * kb );
167 return temperature;
168 }
169
170 double Thermo::getPressure(){
171 // returns pressure in units amu*fs^-2*Ang^-1
172 // routine derived via viral theorem description in:
173 // Paci, E. and Marchi, M. J.Phys.Chem. 1996, 100, 4314-4322
174
175 return 0.0;
176 }
177
178 void Thermo::velocitize() {
179
180 double x,y;
181 double vx, vy, vz;
182 double jx, jy, jz;
183 int i, vr, vd; // velocity randomizer loop counters
184 double vdrift[3];
185 double vbar;
186 const double kb = 8.31451e-7; // kb in amu, angstroms, fs, etc.
187 double av2;
188 double kebar;
189 int ndf, ndf_local; // number of degrees of freedom
190 int ndfRaw, ndfRaw_local; // the raw number of degrees of freedom
191 int n_atoms;
192 Atom** atoms;
193 DirectionalAtom* dAtom;
194 double temperature;
195 int n_oriented;
196 int n_constraints;
197
198 atoms = entry_plug->atoms;
199 n_atoms = entry_plug->n_atoms;
200 temperature = entry_plug->target_temp;
201 n_oriented = entry_plug->n_oriented;
202 n_constraints = entry_plug->n_constraints;
203
204 kebar = kb * temperature * (double)this->getNDF() /
205 ( 2.0 * (double)this->getNDFraw() );
206
207 for(vr = 0; vr < n_atoms; vr++){
208
209 // uses equipartition theory to solve for vbar in angstrom/fs
210
211 av2 = 2.0 * kebar / atoms[vr]->getMass();
212 vbar = sqrt( av2 );
213
214 // vbar = sqrt( 8.31451e-7 * temperature / atoms[vr]->getMass() );
215
216 // picks random velocities from a gaussian distribution
217 // centered on vbar
218
219 vx = vbar * gaussStream->getGaussian();
220 vy = vbar * gaussStream->getGaussian();
221 vz = vbar * gaussStream->getGaussian();
222
223 atoms[vr]->set_vx( vx );
224 atoms[vr]->set_vy( vy );
225 atoms[vr]->set_vz( vz );
226 }
227
228 // Get the Center of Mass drift velocity.
229
230 getCOMVel(vdrift);
231
232 // Corrects for the center of mass drift.
233 // sums all the momentum and divides by total mass.
234
235 for(vd = 0; vd < n_atoms; vd++){
236
237 vx = atoms[vd]->get_vx();
238 vy = atoms[vd]->get_vy();
239 vz = atoms[vd]->get_vz();
240
241 vx -= vdrift[0];
242 vy -= vdrift[1];
243 vz -= vdrift[2];
244
245 atoms[vd]->set_vx(vx);
246 atoms[vd]->set_vy(vy);
247 atoms[vd]->set_vz(vz);
248 }
249 if( n_oriented ){
250
251 for( i=0; i<n_atoms; i++ ){
252
253 if( atoms[i]->isDirectional() ){
254
255 dAtom = (DirectionalAtom *)atoms[i];
256
257 vbar = sqrt( 2.0 * kebar * dAtom->getIxx() );
258 jx = vbar * gaussStream->getGaussian();
259
260 vbar = sqrt( 2.0 * kebar * dAtom->getIyy() );
261 jy = vbar * gaussStream->getGaussian();
262
263 vbar = sqrt( 2.0 * kebar * dAtom->getIzz() );
264 jz = vbar * gaussStream->getGaussian();
265
266 dAtom->setJx( jx );
267 dAtom->setJy( jy );
268 dAtom->setJz( jz );
269 }
270 }
271 }
272 }
273
274 void Thermo::getCOMVel(double vdrift[3]){
275
276 double mtot, mtot_local;
277 double vdrift_local[3];
278 int vd, n_atoms;
279 Atom** atoms;
280
281 // We are very careless here with the distinction between n_atoms and n_local
282 // We should really fix this before someone pokes an eye out.
283
284 n_atoms = entry_plug->n_atoms;
285 atoms = entry_plug->atoms;
286
287 mtot_local = 0.0;
288 vdrift_local[0] = 0.0;
289 vdrift_local[1] = 0.0;
290 vdrift_local[2] = 0.0;
291
292 for(vd = 0; vd < n_atoms; vd++){
293
294 vdrift_local[0] += atoms[vd]->get_vx() * atoms[vd]->getMass();
295 vdrift_local[1] += atoms[vd]->get_vy() * atoms[vd]->getMass();
296 vdrift_local[2] += atoms[vd]->get_vz() * atoms[vd]->getMass();
297
298 mtot_local += atoms[vd]->getMass();
299 }
300
301 #ifdef IS_MPI
302 MPI_Allreduce(&mtot_local,&mtot,1,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
303 MPI_Allreduce(vdrift_local,vdrift,3,MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
304 #else
305 mtot = mtot_local;
306 for(vd = 0; vd < 3; vd++) {
307 vdrift[vd] = vdrift_local[vd];
308 }
309 #endif
310
311 for (vd = 0; vd < 3; vd++) {
312 vdrift[vd] = vdrift[vd] / mtot;
313 }
314
315 }
316