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root/group/trunk/mdtools/md_code/Thermo.cpp
Revision: 252
Committed: Tue Jan 28 22:16:55 2003 UTC (21 years, 5 months ago) by chuckv
File size: 7292 byte(s)
Log Message:
Force loops seems to work, velocitize never being called....

File Contents

# User Rev Content
1 mmeineke 10 #include <cmath>
2 chuckv 252 #include <iostream>
3 chuckv 249
4 chuckv 252
5 chuckv 249 #ifdef IS_MPI
6 chuckv 218 #include <mpi++.h>
7 chuckv 249 #endif //is_mpi
8 mmeineke 10
9     #include "Thermo.hpp"
10     #include "SRI.hpp"
11     #include "LRI.hpp"
12     #include "Integrator.hpp"
13    
14 chuckv 223 #define BASE_SEED 123456789
15 mmeineke 10
16 chuckv 223 Thermo::Thermo( SimInfo* the_entry_plug ) {
17     entry_plug = the_entry_plug;
18 chuckv 249 int baseSeed = BASE_SEED;
19 chuckv 223 gaussStream = new gaussianSPRNG( baseSeed );
20     }
21    
22     Thermo::~Thermo(){
23     delete gaussStream;
24     }
25    
26 mmeineke 10 double Thermo::getKinetic(){
27    
28     const double e_convert = 4.184E-4; // convert kcal/mol -> (amu A^2)/fs^2
29     double vx2, vy2, vz2;
30     double kinetic, v_sqr;
31     int kl;
32     double jx2, jy2, jz2; // the square of the angular momentums
33    
34     DirectionalAtom *dAtom;
35    
36     int n_atoms;
37 chuckv 218 double kinetic_global;
38 mmeineke 10 Atom** atoms;
39 chuckv 218
40 mmeineke 10
41     n_atoms = entry_plug->n_atoms;
42     atoms = entry_plug->atoms;
43    
44     kinetic = 0.0;
45 chuckv 218 kinetic_global = 0.0;
46 mmeineke 10 for( kl=0; kl < n_atoms; kl++ ){
47    
48     vx2 = atoms[kl]->get_vx() * atoms[kl]->get_vx();
49     vy2 = atoms[kl]->get_vy() * atoms[kl]->get_vy();
50     vz2 = atoms[kl]->get_vz() * atoms[kl]->get_vz();
51    
52     v_sqr = vx2 + vy2 + vz2;
53     kinetic += atoms[kl]->getMass() * v_sqr;
54    
55     if( atoms[kl]->isDirectional() ){
56    
57     dAtom = (DirectionalAtom *)atoms[kl];
58    
59     jx2 = dAtom->getJx() * dAtom->getJx();
60     jy2 = dAtom->getJy() * dAtom->getJy();
61     jz2 = dAtom->getJz() * dAtom->getJz();
62    
63     kinetic += (jx2 / dAtom->getIxx()) + (jy2 / dAtom->getIyy())
64     + (jz2 / dAtom->getIzz());
65     }
66     }
67 chuckv 218 #ifdef IS_MPI
68     MPI_COMM_WORLD.Allreduce(&kinetic,&kinetic_global,1,MPI_DOUBLE,MPI_SUM);
69     kinetic = kinetic_global;
70 chuckv 249 #endif //is_mpi
71 chuckv 218
72 mmeineke 10 kinetic = kinetic * 0.5 / e_convert;
73    
74     return kinetic;
75     }
76    
77     double Thermo::getPotential(){
78    
79     double potential;
80 chuckv 218 double potential_global;
81 mmeineke 10 int el, nSRI;
82     SRI** sris;
83    
84     sris = entry_plug->sr_interactions;
85     nSRI = entry_plug->n_SRI;
86    
87     potential = 0.0;
88 chuckv 218 potential_global = 0.0;
89 chuckv 249 potential += entry_plug->lrPot;
90 mmeineke 10
91     // std::cerr << "long range potential: " << potential << "\n";
92     for( el=0; el<nSRI; el++ ){
93    
94     potential += sris[el]->get_potential();
95     }
96    
97 chuckv 218 // Get total potential for entire system from MPI.
98     #ifdef IS_MPI
99     MPI_COMM_WORLD.Allreduce(&potential,&potential_global,1,MPI_DOUBLE,MPI_SUM);
100     potential = potential_global;
101 chuckv 249 #endif // is_mpi
102 chuckv 218
103 mmeineke 10 return potential;
104     }
105    
106     double Thermo::getTotalE(){
107    
108     double total;
109    
110     total = this->getKinetic() + this->getPotential();
111     return total;
112     }
113    
114     double Thermo::getTemperature(){
115    
116 mmeineke 25 const double kb = 1.9872179E-3; // boltzman's constant in kcal/(mol K)
117 mmeineke 10 double temperature;
118    
119     int ndf = 3 * entry_plug->n_atoms + 3 * entry_plug->n_oriented
120     - entry_plug->n_constraints - 3;
121    
122     temperature = ( 2.0 * this->getKinetic() ) / ( ndf * kb );
123     return temperature;
124     }
125    
126     double Thermo::getPressure(){
127    
128 mmeineke 117 // const double conv_Pa_atm = 9.901E-6; // convert Pa -> atm
129     // const double conv_internal_Pa = 1.661E-7; //convert amu/(fs^2 A) -> Pa
130     // const double conv_A_m = 1.0E-10; //convert A -> m
131 mmeineke 10
132     return 0.0;
133     }
134    
135     void Thermo::velocitize() {
136    
137     double x,y;
138     double vx, vy, vz;
139     double jx, jy, jz;
140     int i, vr, vd; // velocity randomizer loop counters
141     double vdrift[3];
142     double mtot = 0.0;
143     double vbar;
144     const double kb = 8.31451e-7; // kb in amu, angstroms, fs, etc.
145     double av2;
146     double kebar;
147     int ndf; // number of degrees of freedom
148     int ndfRaw; // the raw number of degrees of freedom
149     int n_atoms;
150     Atom** atoms;
151     DirectionalAtom* dAtom;
152     double temperature;
153     int n_oriented;
154     int n_constraints;
155    
156     atoms = entry_plug->atoms;
157     n_atoms = entry_plug->n_atoms;
158     temperature = entry_plug->target_temp;
159     n_oriented = entry_plug->n_oriented;
160     n_constraints = entry_plug->n_constraints;
161    
162    
163     ndfRaw = 3 * n_atoms + 3 * n_oriented;
164     ndf = ndfRaw - n_constraints - 3;
165     kebar = kb * temperature * (double)ndf / ( 2.0 * (double)ndfRaw );
166    
167 chuckv 252 printf("Entered Velocitize\n");
168 mmeineke 10 for(vr = 0; vr < n_atoms; vr++){
169    
170     // uses equipartition theory to solve for vbar in angstrom/fs
171    
172     av2 = 2.0 * kebar / atoms[vr]->getMass();
173     vbar = sqrt( av2 );
174    
175     // vbar = sqrt( 8.31451e-7 * temperature / atoms[vr]->getMass() );
176    
177     // picks random velocities from a gaussian distribution
178     // centered on vbar
179 chuckv 221 #ifndef USE_SPRNG
180     /* If we are using mpi, we need to use the SPRNG random
181     generator. The non drand48 generator will just repeat
182     the same numbers for every node creating a non-gaussian
183     distribution for the simulation. drand48 is fine for the
184     single processor version of the code, but SPRNG should
185     still be preferred for consistency.
186     */
187 chuckv 249
188 chuckv 221 #ifdef IS_MPI
189     #error "SPRNG random number generator must be used for MPI"
190     #else
191     #warning "Using drand48 for random number generation"
192 chuckv 249 #endif // is_mpi
193    
194 mmeineke 10 x = drand48();
195     y = drand48();
196     vx = vbar * sqrt( -2.0 * log(x)) * cos(2 * M_PI * y);
197    
198     x = drand48();
199     y = drand48();
200     vy = vbar * sqrt( -2.0 * log(x)) * cos(2 * M_PI * y);
201    
202     x = drand48();
203     y = drand48();
204     vz = vbar * sqrt( -2.0 * log(x)) * cos(2 * M_PI * y);
205 chuckv 252 printf("Setting new velocities vx: %f\n",vx);
206 chuckv 249 #endif // use_spring
207 chuckv 221
208     #ifdef USE_SPRNG
209 chuckv 223 vx = vbar * gaussStream->getGaussian();
210     vy = vbar * gaussStream->getGaussian();
211     vz = vbar * gaussStream->getGaussian();
212 chuckv 249 #endif // use_spring
213 chuckv 221
214 mmeineke 10 atoms[vr]->set_vx( vx );
215     atoms[vr]->set_vy( vy );
216     atoms[vr]->set_vz( vz );
217     }
218    
219     // Corrects for the center of mass drift.
220     // sums all the momentum and divides by total mass.
221    
222     mtot = 0.0;
223     vdrift[0] = 0.0;
224     vdrift[1] = 0.0;
225     vdrift[2] = 0.0;
226     for(vd = 0; vd < n_atoms; vd++){
227    
228     vdrift[0] += atoms[vd]->get_vx() * atoms[vd]->getMass();
229     vdrift[1] += atoms[vd]->get_vy() * atoms[vd]->getMass();
230     vdrift[2] += atoms[vd]->get_vz() * atoms[vd]->getMass();
231    
232     mtot = mtot + atoms[vd]->getMass();
233     }
234    
235     for (vd = 0; vd < 3; vd++) {
236     vdrift[vd] = vdrift[vd] / mtot;
237     }
238    
239     for(vd = 0; vd < n_atoms; vd++){
240    
241     vx = atoms[vd]->get_vx();
242     vy = atoms[vd]->get_vy();
243     vz = atoms[vd]->get_vz();
244    
245    
246     vx -= vdrift[0];
247     vy -= vdrift[1];
248     vz -= vdrift[2];
249    
250     atoms[vd]->set_vx(vx);
251     atoms[vd]->set_vy(vy);
252     atoms[vd]->set_vz(vz);
253     }
254     if( n_oriented ){
255    
256     for( i=0; i<n_atoms; i++ ){
257    
258     if( atoms[i]->isDirectional() ){
259    
260     dAtom = (DirectionalAtom *)atoms[i];
261 chuckv 249
262     #ifndef USE_SPRNG
263    
264 chuckv 221 #ifdef IS_MPI
265     #error "SPRNG random number generator must be used for MPI"
266 chuckv 249 #else // is_mpi
267 chuckv 221 #warning "Using drand48 for random number generation"
268 chuckv 249 #endif // is_MPI
269 mmeineke 10
270     vbar = sqrt( 2.0 * kebar * dAtom->getIxx() );
271     x = drand48();
272     y = drand48();
273     jx = vbar * sqrt( -2.0 * log(x)) * cos(2 * M_PI * y);
274    
275     vbar = sqrt( 2.0 * kebar * dAtom->getIyy() );
276     x = drand48();
277     y = drand48();
278     jy = vbar * sqrt( -2.0 * log(x)) * cos(2 * M_PI * y);
279    
280     vbar = sqrt( 2.0 * kebar * dAtom->getIzz() );
281     x = drand48();
282     y = drand48();
283     jz = vbar * sqrt( -2.0 * log(x)) * cos(2 * M_PI * y);
284 chuckv 249
285     #else //use_sprng
286    
287 chuckv 221 vbar = sqrt( 2.0 * kebar * dAtom->getIxx() );
288 chuckv 223 jx = vbar * gaussStream->getGaussian();
289 chuckv 221
290     vbar = sqrt( 2.0 * kebar * dAtom->getIyy() );
291 chuckv 223 jy = vbar * gaussStream->getGaussian();
292 chuckv 221
293     vbar = sqrt( 2.0 * kebar * dAtom->getIzz() );
294 chuckv 223 jz = vbar * gaussStream->getGaussian();
295 chuckv 249 #endif //use_sprng
296 mmeineke 10
297     dAtom->setJx( jx );
298     dAtom->setJy( jy );
299     dAtom->setJz( jz );
300     }
301     }
302     }
303     }