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Comparing trunk/OOPSE/libmdtools/NVT.cpp (file contents):
Revision 645 by tim, Tue Jul 22 19:54:52 2003 UTC vs.
Revision 855 by mmeineke, Thu Nov 6 22:01:37 2003 UTC

# Line 1 | Line 1
1 + #include <math.h>
2 +
3   #include "Atom.hpp"
4   #include "SRI.hpp"
5   #include "AbstractClasses.hpp"
# Line 6 | Line 8
8   #include "Thermo.hpp"
9   #include "ReadWrite.hpp"
10   #include "Integrator.hpp"
11 < #include "simError.h"
11 > #include "simError.h"
12  
13  
14   // Basic thermostating via Hoover, Phys.Rev.A, 1985, Vol. 31 (5) 1695-1697
# Line 14 | Line 16 | template<typename T> NVT<T>::NVT ( SimInfo *theInfo, F
16   template<typename T> NVT<T>::NVT ( SimInfo *theInfo, ForceFields* the_ff):
17    T( theInfo, the_ff )
18   {
19 +  GenericData* data;
20 +  DoubleData * chiValue;
21 +  DoubleData * integralOfChidtValue;
22 +
23 +  chiValue = NULL;
24 +  integralOfChidtValue = NULL;
25 +
26    chi = 0.0;
27    have_tau_thermostat = 0;
28    have_target_temp = 0;
29 +  have_chi_tolerance = 0;
30 +  integralOfChidt = 0.0;
31 +
32 +
33 +  if( theInfo->useInitXSstate ){
34 +
35 +    // retrieve chi and integralOfChidt from simInfo
36 +    data = info->getProperty(CHIVALUE_ID);
37 +    if(data){
38 +      chiValue = dynamic_cast<DoubleData*>(data);
39 +    }
40 +    
41 +    data = info->getProperty(INTEGRALOFCHIDT_ID);
42 +    if(data){
43 +      integralOfChidtValue = dynamic_cast<DoubleData*>(data);
44 +    }
45 +    
46 +    // chi and integralOfChidt should appear by pair
47 +    if(chiValue && integralOfChidtValue){
48 +      chi = chiValue->getData();
49 +      integralOfChidt = integralOfChidtValue->getData();
50 +    }
51 +  }
52 +
53 +  oldVel = new double[3*nAtoms];
54 +  oldJi = new double[3*nAtoms];
55   }
56  
57 + template<typename T> NVT<T>::~NVT() {
58 +  delete[] oldVel;
59 +  delete[] oldJi;
60 + }
61 +
62   template<typename T> void NVT<T>::moveA() {
63 <  
63 >
64    int i, j;
65    DirectionalAtom* dAtom;
66    double Tb[3], ji[3];
67 <  double A[3][3], I[3][3];
28 <  double angle, mass;
67 >  double mass;
68    double vel[3], pos[3], frc[3];
69  
70    double instTemp;
71  
72 +  // We need the temperature at time = t for the chi update below:
73 +
74    instTemp = tStats->getTemperature();
75  
35 –  // first evolve chi a half step
36 –  
37 –  chi += dt2 * ( instTemp / targetTemp - 1.0) / (tauThermostat*tauThermostat);
38 –
76    for( i=0; i<nAtoms; i++ ){
77  
78      atoms[i]->getVel( vel );
# Line 45 | Line 82 | template<typename T> void NVT<T>::moveA() {
82      mass = atoms[i]->getMass();
83  
84      for (j=0; j < 3; j++) {
85 <      // velocity half step
85 >      // velocity half step  (use chi from previous step here):
86        vel[j] += dt2 * ((frc[j] / mass ) * eConvert - vel[j]*chi);
87        // position whole step
88        pos[j] += dt * vel[j];
# Line 53 | Line 90 | template<typename T> void NVT<T>::moveA() {
90  
91      atoms[i]->setVel( vel );
92      atoms[i]->setPos( pos );
93 <  
93 >
94      if( atoms[i]->isDirectional() ){
95  
96        dAtom = (DirectionalAtom *)atoms[i];
97 <          
97 >
98        // get and convert the torque to body frame
99 <      
99 >
100        dAtom->getTrq( Tb );
101        dAtom->lab2Body( Tb );
102 <      
102 >
103        // get the angular momentum, and propagate a half step
104  
105        dAtom->getJ( ji );
106  
107 <      for (j=0; j < 3; j++)
107 >      for (j=0; j < 3; j++)
108          ji[j] += dt2 * (Tb[j] * eConvert - ji[j]*chi);
72 –      
73 –      // use the angular velocities to propagate the rotation matrix a
74 –      // full time step
109  
110 <      dAtom->getA(A);
77 <      dAtom->getI(I);
78 <    
79 <      // rotate about the x-axis      
80 <      angle = dt2 * ji[0] / I[0][0];
81 <      this->rotate( 1, 2, angle, ji, A );
110 >      this->rotationPropagation( dAtom, ji );
111  
83 –      // rotate about the y-axis
84 –      angle = dt2 * ji[1] / I[1][1];
85 –      this->rotate( 2, 0, angle, ji, A );
86 –      
87 –      // rotate about the z-axis
88 –      angle = dt * ji[2] / I[2][2];
89 –      this->rotate( 0, 1, angle, ji, A);
90 –      
91 –      // rotate about the y-axis
92 –      angle = dt2 * ji[1] / I[1][1];
93 –      this->rotate( 2, 0, angle, ji, A );
94 –      
95 –       // rotate about the x-axis
96 –      angle = dt2 * ji[0] / I[0][0];
97 –      this->rotate( 1, 2, angle, ji, A );
98 –      
112        dAtom->setJ( ji );
113 <      dAtom->setA( A  );    
101 <    }    
113 >    }
114    }
115 +
116 +  if (nConstrained){
117 +    constrainA();
118 +  }
119 +
120 +  // Finally, evolve chi a half step (just like a velocity) using
121 +  // temperature at time t, not time t+dt/2
122 +
123 +  chi += dt2 * ( instTemp / targetTemp - 1.0) / (tauThermostat*tauThermostat);
124 +  integralOfChidt += chi*dt2;
125 +
126   }
127  
128   template<typename T> void NVT<T>::moveB( void ){
129 <  int i, j;
129 >  int i, j, k;
130    DirectionalAtom* dAtom;
131    double Tb[3], ji[3];
132    double vel[3], frc[3];
133    double mass;
111 –
134    double instTemp;
135 <  
136 <  instTemp = tStats->getTemperature();
137 <  chi += dt2 * ( instTemp / targetTemp - 1.0) / (tauThermostat*tauThermostat);
138 <  
135 >  double oldChi, prevChi;
136 >
137 >  // Set things up for the iteration:
138 >
139 >  oldChi = chi;
140 >
141    for( i=0; i<nAtoms; i++ ){
142  
143      atoms[i]->getVel( vel );
120 –    atoms[i]->getFrc( frc );
144  
145 <    mass = atoms[i]->getMass();
145 >    for (j=0; j < 3; j++)
146 >      oldVel[3*i + j]  = vel[j];
147  
124 –    // velocity half step
125 –    for (j=0; j < 3; j++)
126 –      vel[j] += dt2 * ((frc[j] / mass ) * eConvert - vel[j]*chi);
127 –    
128 –    atoms[i]->setVel( vel );
129 –
148      if( atoms[i]->isDirectional() ){
149  
150        dAtom = (DirectionalAtom *)atoms[i];
151  
152 <      // get and convert the torque to body frame      
152 >      dAtom->getJ( ji );
153  
154 <      dAtom->getTrq( Tb );
155 <      dAtom->lab2Body( Tb );
154 >      for (j=0; j < 3; j++)
155 >        oldJi[3*i + j] = ji[j];
156  
157 <      // get the angular momentum, and propagate a half step
157 >    }
158 >  }
159  
160 <      dAtom->getJ( ji );
160 >  // do the iteration:
161  
162 <      for (j=0; j < 3; j++)
144 <        ji[j] += dt2 * (Tb[j] * eConvert - ji[j]*chi);
145 <      
162 >  for (k=0; k < 4; k++) {
163  
164 <      dAtom->setJ( ji );
164 >    instTemp = tStats->getTemperature();
165 >
166 >    // evolve chi another half step using the temperature at t + dt/2
167 >
168 >    prevChi = chi;
169 >    chi = oldChi + dt2 * ( instTemp / targetTemp - 1.0) /
170 >      (tauThermostat*tauThermostat);
171 >
172 >    for( i=0; i<nAtoms; i++ ){
173 >
174 >      atoms[i]->getFrc( frc );
175 >      atoms[i]->getVel(vel);
176 >
177 >      mass = atoms[i]->getMass();
178 >
179 >      // velocity half step
180 >      for (j=0; j < 3; j++)
181 >        vel[j] = oldVel[3*i+j] + dt2 * ((frc[j] / mass ) * eConvert - oldVel[3*i + j]*chi);
182 >
183 >      atoms[i]->setVel( vel );
184 >
185 >      if( atoms[i]->isDirectional() ){
186 >
187 >        dAtom = (DirectionalAtom *)atoms[i];
188 >
189 >        // get and convert the torque to body frame
190 >
191 >        dAtom->getTrq( Tb );
192 >        dAtom->lab2Body( Tb );
193 >
194 >        for (j=0; j < 3; j++)
195 >          ji[j] = oldJi[3*i + j] + dt2 * (Tb[j] * eConvert - oldJi[3*i+j]*chi);
196 >
197 >        dAtom->setJ( ji );
198 >      }
199      }
200 +
201 +    if (nConstrained){
202 +      constrainB();
203 +    }
204 +
205 +    if (fabs(prevChi - chi) <= chiTolerance) break;
206    }
207 +
208 +  integralOfChidt += dt2*chi;
209   }
210  
211 + template<typename T> void NVT<T>::resetIntegrator( void ){
212 +
213 +  chi = 0.0;
214 +  integralOfChidt = 0.0;
215 + }
216 +
217   template<typename T> int NVT<T>::readyCheck() {
218 <
219 <  // First check to see if we have a target temperature.
220 <  // Not having one is fatal.
221 <  
218 >
219 >  //check parent's readyCheck() first
220 >  if (T::readyCheck() == -1)
221 >    return -1;
222 >
223 >  // First check to see if we have a target temperature.
224 >  // Not having one is fatal.
225 >
226    if (!have_target_temp) {
227      sprintf( painCave.errMsg,
228               "NVT error: You can't use the NVT integrator without a targetTemp!\n"
# Line 162 | Line 231 | template<typename T> int NVT<T>::readyCheck() {
231      simError();
232      return -1;
233    }
234 <  
234 >
235    // We must set tauThermostat.
236 <  
236 >
237    if (!have_tau_thermostat) {
238      sprintf( painCave.errMsg,
239               "NVT error: If you use the constant temperature\n"
# Line 172 | Line 241 | template<typename T> int NVT<T>::readyCheck() {
241      painCave.isFatal = 1;
242      simError();
243      return -1;
244 <  }    
244 >  }
245 >
246 >  if (!have_chi_tolerance) {
247 >    sprintf( painCave.errMsg,
248 >             "NVT warning: setting chi tolerance to 1e-6\n");
249 >    chiTolerance = 1e-6;
250 >    have_chi_tolerance = 1;
251 >    painCave.isFatal = 0;
252 >    simError();
253 >  }
254 >
255    return 1;
256 +
257   }
258 +
259 + template<typename T> double NVT<T>::getConservedQuantity(void){
260 +
261 +  double conservedQuantity;
262 +  double fkBT;
263 +  double Energy;
264 +  double thermostat_kinetic;
265 +  double thermostat_potential;
266 +
267 +  fkBT = (double)(info->getNDF()    ) * kB * targetTemp;
268 +
269 +  Energy = tStats->getTotalE();
270 +
271 +  thermostat_kinetic = fkBT* tauThermostat * tauThermostat * chi * chi /
272 +    (2.0 * eConvert);
273 +
274 +  thermostat_potential = fkBT * integralOfChidt / eConvert;
275 +
276 +  conservedQuantity = Energy + thermostat_kinetic + thermostat_potential;
277 +
278 +  return conservedQuantity;
279 + }
280 +
281 + template<typename T> string NVT<T>::getAdditionalParameters(void){
282 +  string parameters;
283 +  const int BUFFERSIZE = 2000; // size of the read buffer
284 +  char buffer[BUFFERSIZE];
285 +
286 +  sprintf(buffer,"\t%G\t%G;", chi, integralOfChidt);
287 +  parameters += buffer;
288 +
289 +  return parameters;
290 + }

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