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root/group/trunk/OOPSE/libmdtools/Thermo.cpp
Revision: 423
Committed: Thu Mar 27 20:12:15 2003 UTC (21 years, 3 months ago) by mmeineke
File size: 7041 byte(s)
Log Message:
I have implemeted Molecules everywhere I could remember to.
will now attempt to compile.

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
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::COMM_WORLD.Allreduce(&kinetic,&kinetic_global,1,MPI_DOUBLE,MPI_SUM);
76 kinetic = kinetic_global;
77 #endif //is_mpi
78
79 kinetic = kinetic * 0.5 / e_convert;
80
81 return kinetic;
82 }
83
84 double Thermo::getPotential(){
85
86 double potential_local;
87 double potential;
88 int el, nSRI;
89 SRI** sris;
90
91 sris = entry_plug->sr_interactions;
92 nSRI = entry_plug->n_SRI;
93
94 potential_local = 0.0;
95 potential_local += entry_plug->lrPot;
96
97 for( el=0; el<entry_plug->n_mol; el++ ){
98 potential_local += entry_plug->molecules[el]->get_potential();
99 }
100
101 // Get total potential for entire system from MPI.
102 #ifdef IS_MPI
103 MPI::COMM_WORLD.Allreduce(&potential_local,&potential,1,MPI_DOUBLE,MPI_SUM);
104 #else
105 potential = potential_local;
106 #endif // is_mpi
107
108 return potential;
109 }
110
111 double Thermo::getTotalE(){
112
113 double total;
114
115 total = this->getKinetic() + this->getPotential();
116 return total;
117 }
118
119 double Thermo::getTemperature(){
120
121 const double kb = 1.9872179E-3; // boltzman's constant in kcal/(mol K)
122 double temperature;
123 int ndf_local, ndf;
124
125 ndf_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented
126 - entry_plug->n_constraints;
127
128 #ifdef IS_MPI
129 MPI::COMM_WORLD.Allreduce(&ndf_local,&ndf,1,MPI_INT,MPI_SUM);
130 #else
131 ndf = ndf_local;
132 #endif
133
134 ndf = ndf - 3;
135
136 temperature = ( 2.0 * this->getKinetic() ) / ( ndf * kb );
137 return temperature;
138 }
139
140 double Thermo::getPressure(){
141
142 // const double conv_Pa_atm = 9.901E-6; // convert Pa -> atm
143 // const double conv_internal_Pa = 1.661E-7; //convert amu/(fs^2 A) -> Pa
144 // const double conv_A_m = 1.0E-10; //convert A -> m
145
146 return 0.0;
147 }
148
149 void Thermo::velocitize() {
150
151 double x,y;
152 double vx, vy, vz;
153 double jx, jy, jz;
154 int i, vr, vd; // velocity randomizer loop counters
155 double vdrift[3];
156 double vbar;
157 const double kb = 8.31451e-7; // kb in amu, angstroms, fs, etc.
158 double av2;
159 double kebar;
160 int ndf, ndf_local; // number of degrees of freedom
161 int ndfRaw, ndfRaw_local; // the raw number of degrees of freedom
162 int n_atoms;
163 Atom** atoms;
164 DirectionalAtom* dAtom;
165 double temperature;
166 int n_oriented;
167 int n_constraints;
168
169 atoms = entry_plug->atoms;
170 n_atoms = entry_plug->n_atoms;
171 temperature = entry_plug->target_temp;
172 n_oriented = entry_plug->n_oriented;
173 n_constraints = entry_plug->n_constraints;
174
175 // Raw degrees of freedom that we have to set
176 ndfRaw_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented;
177
178 // Degrees of freedom that can contain kinetic energy
179 ndf_local = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented
180 - entry_plug->n_constraints;
181
182 #ifdef IS_MPI
183 MPI::COMM_WORLD.Allreduce(&ndf_local,&ndf,1,MPI_INT,MPI_SUM);
184 MPI::COMM_WORLD.Allreduce(&ndfRaw_local,&ndfRaw,1,MPI_INT,MPI_SUM);
185 #else
186 ndfRaw = ndfRaw_local;
187 ndf = ndf_local;
188 #endif
189 ndf = ndf - 3;
190
191 kebar = kb * temperature * (double)ndf / ( 2.0 * (double)ndfRaw );
192
193 for(vr = 0; vr < n_atoms; vr++){
194
195 // uses equipartition theory to solve for vbar in angstrom/fs
196
197 av2 = 2.0 * kebar / atoms[vr]->getMass();
198 vbar = sqrt( av2 );
199
200 // vbar = sqrt( 8.31451e-7 * temperature / atoms[vr]->getMass() );
201
202 // picks random velocities from a gaussian distribution
203 // centered on vbar
204
205 vx = vbar * gaussStream->getGaussian();
206 vy = vbar * gaussStream->getGaussian();
207 vz = vbar * gaussStream->getGaussian();
208
209 atoms[vr]->set_vx( vx );
210 atoms[vr]->set_vy( vy );
211 atoms[vr]->set_vz( vz );
212 }
213
214 // Get the Center of Mass drift velocity.
215
216 getCOMVel(vdrift);
217
218 // Corrects for the center of mass drift.
219 // sums all the momentum and divides by total mass.
220
221 for(vd = 0; vd < n_atoms; vd++){
222
223 vx = atoms[vd]->get_vx();
224 vy = atoms[vd]->get_vy();
225 vz = atoms[vd]->get_vz();
226
227 vx -= vdrift[0];
228 vy -= vdrift[1];
229 vz -= vdrift[2];
230
231 atoms[vd]->set_vx(vx);
232 atoms[vd]->set_vy(vy);
233 atoms[vd]->set_vz(vz);
234 }
235 if( n_oriented ){
236
237 for( i=0; i<n_atoms; i++ ){
238
239 if( atoms[i]->isDirectional() ){
240
241 dAtom = (DirectionalAtom *)atoms[i];
242
243 vbar = sqrt( 2.0 * kebar * dAtom->getIxx() );
244 jx = vbar * gaussStream->getGaussian();
245
246 vbar = sqrt( 2.0 * kebar * dAtom->getIyy() );
247 jy = vbar * gaussStream->getGaussian();
248
249 vbar = sqrt( 2.0 * kebar * dAtom->getIzz() );
250 jz = vbar * gaussStream->getGaussian();
251
252 dAtom->setJx( jx );
253 dAtom->setJy( jy );
254 dAtom->setJz( jz );
255 }
256 }
257 }
258 }
259
260 void Thermo::getCOMVel(double vdrift[3]){
261
262 double mtot, mtot_local;
263 double vdrift_local[3];
264 int vd, n_atoms;
265 Atom** atoms;
266
267 // We are very careless here with the distinction between n_atoms and n_local
268 // We should really fix this before someone pokes an eye out.
269
270 n_atoms = entry_plug->n_atoms;
271 atoms = entry_plug->atoms;
272
273 mtot_local = 0.0;
274 vdrift_local[0] = 0.0;
275 vdrift_local[1] = 0.0;
276 vdrift_local[2] = 0.0;
277
278 for(vd = 0; vd < n_atoms; vd++){
279
280 vdrift_local[0] += atoms[vd]->get_vx() * atoms[vd]->getMass();
281 vdrift_local[1] += atoms[vd]->get_vy() * atoms[vd]->getMass();
282 vdrift_local[2] += atoms[vd]->get_vz() * atoms[vd]->getMass();
283
284 mtot_local += atoms[vd]->getMass();
285 }
286
287 #ifdef IS_MPI
288 MPI::COMM_WORLD.Allreduce(&mtot_local,&mtot,1,MPI_DOUBLE,MPI_SUM);
289 MPI::COMM_WORLD.Allreduce(vdrift_local,vdrift,3,MPI_DOUBLE,MPI_SUM);
290 #else
291 mtot = mtot_local;
292 for(vd = 0; vd < 3; vd++) {
293 vdrift[vd] = vdrift_local[vd];
294 }
295 #endif
296
297 for (vd = 0; vd < 3; vd++) {
298 vdrift[vd] = vdrift[vd] / mtot;
299 }
300
301 }
302