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root/group/trunk/OOPSE/libmdtools/Thermo.cpp
Revision: 447
Committed: Thu Apr 3 20:21:54 2003 UTC (21 years, 3 months ago) by mmeineke
File size: 7177 byte(s)
Log Message:
fixed some small things with simError.h

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