src/integrators/NVT.cpp

/*
 * Copyright (c) 2005 The University of Notre Dame. All Rights Reserved.
 *
 * The University of Notre Dame grants you ("Licensee") a
 * non-exclusive, royalty free, license to use, modify and
 * redistribute this software in source and binary code form, provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. All express or implied conditions, representations and
 * warranties, including any implied warranty of merchantability,
 * fitness for a particular purpose or non-infringement, are hereby
 * excluded.  The University of Notre Dame and its licensors shall not
 * be liable for any damages suffered by licensee as a result of
 * using, modifying or distributing the software or its
 * derivatives. In no event will the University of Notre Dame or its
 * licensors be liable for any lost revenue, profit or data, or for
 * direct, indirect, special, consequential, incidental or punitive
 * damages, however caused and regardless of the theory of liability,
 * arising out of the use of or inability to use software, even if the
 * University of Notre Dame has been advised of the possibility of
 * such damages.
 *
 * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your
 * research, please cite the appropriate papers when you publish your
 * work.  Good starting points are:
 *                                                                      
 * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).             
 * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).          
 * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008).          
 * [4]  Vardeman & Gezelter, in progress (2009).                        
 */
 
#include "integrators/NVT.hpp"
#include "primitives/Molecule.hpp"
#include "utils/simError.h"
#include "utils/PhysicalConstants.hpp"

namespace OpenMD {

  NVT::NVT(SimInfo* info) : VelocityVerletIntegrator(info), chiTolerance_ (1e-6), maxIterNum_(4) {

    Globals* simParams = info_->getSimParams();

    if (!simParams->getUseIntialExtendedSystemState()) {
      Snapshot* currSnapshot = info_->getSnapshotManager()->getCurrentSnapshot();
      currSnapshot->setChi(0.0);
      currSnapshot->setIntegralOfChiDt(0.0);
    }
    
    if (!simParams->haveTargetTemp()) {
      sprintf(painCave.errMsg, "You can't use the NVT integrator without a targetTemp_!\n");
      painCave.isFatal = 1;
      painCave.severity = OPENMD_ERROR;
      simError();
    } else {
      targetTemp_ = simParams->getTargetTemp();
    }

    // We must set tauThermostat.

    if (!simParams->haveTauThermostat()) {
      sprintf(painCave.errMsg, "If you use the constant temperature\n"
              "\tintegrator, you must set tauThermostat.\n");

      painCave.severity = OPENMD_ERROR;
      painCave.isFatal = 1;
      simError();
    } else {
      tauThermostat_ = simParams->getTauThermostat();
    }

    update();
  }

  void NVT::doUpdate() {
    oldVel_.resize(info_->getNIntegrableObjects());
    oldJi_.resize(info_->getNIntegrableObjects());    
  }
  void NVT::moveA() {
    SimInfo::MoleculeIterator i;
    Molecule::IntegrableObjectIterator  j;
    Molecule* mol;
    StuntDouble* integrableObject;
    Vector3d Tb;
    Vector3d ji;
    RealType mass;
    Vector3d vel;
    Vector3d pos;
    Vector3d frc;

    RealType chi = currentSnapshot_->getChi();
    RealType integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
    
    // We need the temperature at time = t for the chi update below:

    RealType instTemp = thermo.getTemperature();

    for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
      for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
           integrableObject = mol->nextIntegrableObject(j)) {

        vel = integrableObject->getVel();
        pos = integrableObject->getPos();
        frc = integrableObject->getFrc();

        mass = integrableObject->getMass();

        // velocity half step  (use chi from previous step here):
        //vel[j] += dt2 * ((frc[j] / mass ) * PhysicalConstants::energyConvert - vel[j]*chi);
        vel += dt2 *PhysicalConstants::energyConvert/mass*frc - dt2*chi*vel;
        
        // position whole step
        //pos[j] += dt * vel[j];
        pos += dt * vel;

        integrableObject->setVel(vel);
        integrableObject->setPos(pos);

        if (integrableObject->isDirectional()) {

          //convert the torque to body frame
          Tb = integrableObject->lab2Body(integrableObject->getTrq());

          // get the angular momentum, and propagate a half step

          ji = integrableObject->getJ();

          //ji[j] += dt2 * (Tb[j] * PhysicalConstants::energyConvert - ji[j]*chi);
          ji += dt2*PhysicalConstants::energyConvert*Tb - dt2*chi *ji;
          rotAlgo->rotate(integrableObject, ji, dt);

          integrableObject->setJ(ji);
        }
      }

    }
    
    rattle->constraintA();

    // Finally, evolve chi a half step (just like a velocity) using
    // temperature at time t, not time t+dt/2

    
    chi += dt2 * (instTemp / targetTemp_ - 1.0) / (tauThermostat_ * tauThermostat_);
    integralOfChidt += chi * dt2;

    currentSnapshot_->setChi(chi);
    currentSnapshot_->setIntegralOfChiDt(integralOfChidt);
  }

  void NVT::moveB() {
    SimInfo::MoleculeIterator i;
    Molecule::IntegrableObjectIterator  j;
    Molecule* mol;
    StuntDouble* integrableObject;
    
    Vector3d Tb;
    Vector3d ji;    
    Vector3d vel;
    Vector3d frc;
    RealType mass;
    RealType instTemp;
    int index;
    // Set things up for the iteration:

    RealType chi = currentSnapshot_->getChi();
    RealType oldChi = chi;
    RealType  prevChi;
    RealType integralOfChidt = currentSnapshot_->getIntegralOfChiDt();

    index = 0;
    for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
      for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
           integrableObject = mol->nextIntegrableObject(j)) {
        oldVel_[index] = integrableObject->getVel();
        oldJi_[index] = integrableObject->getJ();                

        ++index;    
      }
           
    }

    // do the iteration:

    for(int k = 0; k < maxIterNum_; k++) {
      index = 0;
      instTemp = thermo.getTemperature();

      // evolve chi another half step using the temperature at t + dt/2

      prevChi = chi;
      chi = oldChi + dt2 * (instTemp / targetTemp_ - 1.0) / (tauThermostat_ * tauThermostat_);

      for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
        for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
             integrableObject = mol->nextIntegrableObject(j)) {

          frc = integrableObject->getFrc();
          vel = integrableObject->getVel();

          mass = integrableObject->getMass();

          // velocity half step
          //for(j = 0; j < 3; j++)
          //    vel[j] = oldVel_[3*i+j] + dt2 * ((frc[j] / mass ) * PhysicalConstants::energyConvert - oldVel_[3*i + j]*chi);
          vel = oldVel_[index] + dt2/mass*PhysicalConstants::energyConvert * frc - dt2*chi*oldVel_[index];
            
          integrableObject->setVel(vel);

          if (integrableObject->isDirectional()) {

            // get and convert the torque to body frame

            Tb =  integrableObject->lab2Body(integrableObject->getTrq());

            //for(j = 0; j < 3; j++)
            //    ji[j] = oldJi_[3*i + j] + dt2 * (Tb[j] * PhysicalConstants::energyConvert - oldJi_[3*i+j]*chi);
            ji = oldJi_[index] + dt2*PhysicalConstants::energyConvert*Tb - dt2*chi *oldJi_[index];

            integrableObject->setJ(ji);
          }


          ++index;
        }
      }
    

      rattle->constraintB();

      if (fabs(prevChi - chi) <= chiTolerance_)
        break;

    }

    integralOfChidt += dt2 * chi;

    currentSnapshot_->setChi(chi);
    currentSnapshot_->setIntegralOfChiDt(integralOfChidt);
  }

  void NVT::resetIntegrator() {
      currentSnapshot_->setChi(0.0);
      currentSnapshot_->setIntegralOfChiDt(0.0);
  }
  
  RealType NVT::calcConservedQuantity() {

    RealType chi = currentSnapshot_->getChi();
    RealType integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
    RealType conservedQuantity;
    RealType fkBT;
    RealType Energy;
    RealType thermostat_kinetic;
    RealType thermostat_potential;
    
    fkBT = info_->getNdf() *PhysicalConstants::kB *targetTemp_;

    Energy = thermo.getTotalE();

    thermostat_kinetic = fkBT * tauThermostat_ * tauThermostat_ * chi * chi / (2.0 * PhysicalConstants::energyConvert);

    thermostat_potential = fkBT * integralOfChidt / PhysicalConstants::energyConvert;

    conservedQuantity = Energy + thermostat_kinetic + thermostat_potential;

    return conservedQuantity;
  }


}//end namespace OpenMD
Revision:	1465
Committed:	Fri Jul 9 23:08:25 2010 UTC (14 years, 9 months ago) by chuckv
File size:	9068 byte(s)
Log Message:	Creating busticated version of OpenMD
#	User	Rev	Content
1	gezelter	507	/*
2	gezelter	246	* Copyright (c) 2005 The University of Notre Dame. All Rights Reserved.
3			*
4			* The University of Notre Dame grants you ("Licensee") a
5			* non-exclusive, royalty free, license to use, modify and
6			* redistribute this software in source and binary code form, provided
7			* that the following conditions are met:
8			*
9	gezelter	1390	* 1. Redistributions of source code must retain the above copyright
10	gezelter	246	* notice, this list of conditions and the following disclaimer.
11			*
12	gezelter	1390	* 2. Redistributions in binary form must reproduce the above copyright
13	gezelter	246	* notice, this list of conditions and the following disclaimer in the
14			* documentation and/or other materials provided with the
15			* distribution.
16			*
17			* This software is provided "AS IS," without a warranty of any
18			* kind. All express or implied conditions, representations and
19			* warranties, including any implied warranty of merchantability,
20			* fitness for a particular purpose or non-infringement, are hereby
21			* excluded. The University of Notre Dame and its licensors shall not
22			* be liable for any damages suffered by licensee as a result of
23			* using, modifying or distributing the software or its
24			* derivatives. In no event will the University of Notre Dame or its
25			* licensors be liable for any lost revenue, profit or data, or for
26			* direct, indirect, special, consequential, incidental or punitive
27			* damages, however caused and regardless of the theory of liability,
28			* arising out of the use of or inability to use software, even if the
29			* University of Notre Dame has been advised of the possibility of
30			* such damages.
31	gezelter	1390	*
32			* SUPPORT OPEN SCIENCE! If you use OpenMD or its source code in your
33			* research, please cite the appropriate papers when you publish your
34			* work. Good starting points are:
35			*
36			* [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).
37			* [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).
38			* [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008).
39			* [4] Vardeman & Gezelter, in progress (2009).
40	gezelter	246	*/
41
42			#include "integrators/NVT.hpp"
43			#include "primitives/Molecule.hpp"
44	tim	3	#include "utils/simError.h"
45	gezelter	1390	#include "utils/PhysicalConstants.hpp"
46	gezelter	2
47	gezelter	1390	namespace OpenMD {
48	gezelter	2
49	gezelter	507	NVT::NVT(SimInfo* info) : VelocityVerletIntegrator(info), chiTolerance_ (1e-6), maxIterNum_(4) {
50	gezelter	2
51	gezelter	246	Globals* simParams = info_->getSimParams();
52	gezelter	2
53	tim	665	if (!simParams->getUseIntialExtendedSystemState()) {
54	gezelter	507	Snapshot* currSnapshot = info_->getSnapshotManager()->getCurrentSnapshot();
55			currSnapshot->setChi(0.0);
56			currSnapshot->setIntegralOfChiDt(0.0);
57	gezelter	246	}
58
59			if (!simParams->haveTargetTemp()) {
60	gezelter	507	sprintf(painCave.errMsg, "You can't use the NVT integrator without a targetTemp_!\n");
61			painCave.isFatal = 1;
62	gezelter	1390	painCave.severity = OPENMD_ERROR;
63	gezelter	507	simError();
64	gezelter	246	} else {
65	gezelter	507	targetTemp_ = simParams->getTargetTemp();
66	gezelter	246	}
67	gezelter	2
68	gezelter	1277	// We must set tauThermostat.
69	gezelter	2
70	gezelter	246	if (!simParams->haveTauThermostat()) {
71	gezelter	507	sprintf(painCave.errMsg, "If you use the constant temperature\n"
72	gezelter	1277	"\tintegrator, you must set tauThermostat.\n");
73	gezelter	2
74	gezelter	1390	painCave.severity = OPENMD_ERROR;
75	gezelter	507	painCave.isFatal = 1;
76			simError();
77	gezelter	246	} else {
78	gezelter	507	tauThermostat_ = simParams->getTauThermostat();
79	gezelter	2	}
80
81	gezelter	246	update();
82	gezelter	507	}
83	gezelter	2
84	gezelter	507	void NVT::doUpdate() {
85	gezelter	246	oldVel_.resize(info_->getNIntegrableObjects());
86			oldJi_.resize(info_->getNIntegrableObjects());
87	gezelter	507	}
88			void NVT::moveA() {
89	gezelter	246	SimInfo::MoleculeIterator i;
90			Molecule::IntegrableObjectIterator j;
91			Molecule* mol;
92			StuntDouble* integrableObject;
93			Vector3d Tb;
94			Vector3d ji;
95	tim	963	RealType mass;
96	gezelter	246	Vector3d vel;
97			Vector3d pos;
98			Vector3d frc;
99	gezelter	2
100	tim	963	RealType chi = currentSnapshot_->getChi();
101			RealType integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
102	gezelter	246
103			// We need the temperature at time = t for the chi update below:
104	gezelter	2
105	tim	963	RealType instTemp = thermo.getTemperature();
106	gezelter	2
107	gezelter	246	for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
108	gezelter	507	for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
109			integrableObject = mol->nextIntegrableObject(j)) {
110	gezelter	2
111	gezelter	246	vel = integrableObject->getVel();
112			pos = integrableObject->getPos();
113			frc = integrableObject->getFrc();
114	gezelter	2
115	gezelter	246	mass = integrableObject->getMass();
116	gezelter	2
117	gezelter	246	// velocity half step (use chi from previous step here):
118	gezelter	1390	//vel[j] += dt2 * ((frc[j] / mass ) * PhysicalConstants::energyConvert - vel[j]*chi);
119			vel += dt2 PhysicalConstants::energyConvert/massfrc - dt2chivel;
120	gezelter	246
121			// position whole step
122			//pos[j] += dt * vel[j];
123			pos += dt * vel;
124	gezelter	2
125	gezelter	246	integrableObject->setVel(vel);
126			integrableObject->setPos(pos);
127	gezelter	2
128	gezelter	246	if (integrableObject->isDirectional()) {
129	gezelter	2
130	gezelter	507	//convert the torque to body frame
131			Tb = integrableObject->lab2Body(integrableObject->getTrq());
132	gezelter	2
133	gezelter	507	// get the angular momentum, and propagate a half step
134	gezelter	2
135	gezelter	507	ji = integrableObject->getJ();
136	gezelter	2
137	gezelter	1390	//ji[j] += dt2 * (Tb[j] * PhysicalConstants::energyConvert - ji[j]*chi);
138			ji += dt2PhysicalConstants::energyConvertTb - dt2chi ji;
139	gezelter	507	rotAlgo->rotate(integrableObject, ji, dt);
140	gezelter	2
141	gezelter	507	integrableObject->setJ(ji);
142	gezelter	246	}
143	gezelter	507	}
144	gezelter	2
145			}
146	gezelter	246
147			rattle->constraintA();
148	gezelter	2
149	gezelter	246	// Finally, evolve chi a half step (just like a velocity) using
150			// temperature at time t, not time t+dt/2
151	gezelter	2
152	gezelter	246
153			chi += dt2 * (instTemp / targetTemp_ - 1.0) / (tauThermostat_ * tauThermostat_);
154			integralOfChidt += chi * dt2;
155	gezelter	2
156	gezelter	246	currentSnapshot_->setChi(chi);
157			currentSnapshot_->setIntegralOfChiDt(integralOfChidt);
158	gezelter	507	}
159	gezelter	2
160	gezelter	507	void NVT::moveB() {
161	gezelter	246	SimInfo::MoleculeIterator i;
162			Molecule::IntegrableObjectIterator j;
163			Molecule* mol;
164			StuntDouble* integrableObject;
165
166			Vector3d Tb;
167			Vector3d ji;
168			Vector3d vel;
169			Vector3d frc;
170	tim	963	RealType mass;
171			RealType instTemp;
172	gezelter	246	int index;
173			// Set things up for the iteration:
174	gezelter	2
175	tim	963	RealType chi = currentSnapshot_->getChi();
176			RealType oldChi = chi;
177			RealType prevChi;
178			RealType integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
179	gezelter	2
180	gezelter	246	index = 0;
181			for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
182	gezelter	507	for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
183			integrableObject = mol->nextIntegrableObject(j)) {
184			oldVel_[index] = integrableObject->getVel();
185			oldJi_[index] = integrableObject->getJ();
186	gezelter	2
187	gezelter	507	++index;
188			}
189	gezelter	246
190	gezelter	2	}
191
192	gezelter	246	// do the iteration:
193	gezelter	2
194	gezelter	246	for(int k = 0; k < maxIterNum_; k++) {
195	gezelter	507	index = 0;
196			instTemp = thermo.getTemperature();
197	gezelter	2
198	gezelter	507	// evolve chi another half step using the temperature at t + dt/2
199	gezelter	2
200	gezelter	507	prevChi = chi;
201			chi = oldChi + dt2 * (instTemp / targetTemp_ - 1.0) / (tauThermostat_ * tauThermostat_);
202	gezelter	2
203	gezelter	507	for (mol = info_->beginMolecule(i); mol != NULL; mol = info_->nextMolecule(i)) {
204			for (integrableObject = mol->beginIntegrableObject(j); integrableObject != NULL;
205			integrableObject = mol->nextIntegrableObject(j)) {
206	gezelter	2
207	gezelter	507	frc = integrableObject->getFrc();
208			vel = integrableObject->getVel();
209	gezelter	2
210	gezelter	507	mass = integrableObject->getMass();
211	gezelter	2
212	gezelter	507	// velocity half step
213			//for(j = 0; j < 3; j++)
214	gezelter	1390	// vel[j] = oldVel_[3i+j] + dt2 ((frc[j] / mass ) * PhysicalConstants::energyConvert - oldVel_[3i + j]chi);
215			vel = oldVel_[index] + dt2/massPhysicalConstants::energyConvert frc - dt2chioldVel_[index];
216	gezelter	246
217	gezelter	507	integrableObject->setVel(vel);
218	gezelter	2
219	gezelter	507	if (integrableObject->isDirectional()) {
220	gezelter	2
221	gezelter	507	// get and convert the torque to body frame
222	gezelter	2
223	gezelter	507	Tb = integrableObject->lab2Body(integrableObject->getTrq());
224	gezelter	2
225	gezelter	507	//for(j = 0; j < 3; j++)
226	gezelter	1390	// ji[j] = oldJi_[3i + j] + dt2 (Tb[j] * PhysicalConstants::energyConvert - oldJi_[3i+j]chi);
227			ji = oldJi_[index] + dt2PhysicalConstants::energyConvertTb - dt2chi oldJi_[index];
228	gezelter	2
229	gezelter	507	integrableObject->setJ(ji);
230			}
231	gezelter	2
232
233	gezelter	507	++index;
234			}
235			}
236	gezelter	2
237
238	gezelter	507	rattle->constraintB();
239	gezelter	2
240	gezelter	507	if (fabs(prevChi - chi) <= chiTolerance_)
241			break;
242	gezelter	2
243	gezelter	246	}
244	gezelter	2
245	gezelter	246	integralOfChidt += dt2 * chi;
246	gezelter	2
247	gezelter	246	currentSnapshot_->setChi(chi);
248			currentSnapshot_->setIntegralOfChiDt(integralOfChidt);
249	gezelter	507	}
250	gezelter	2
251	tim	546	void NVT::resetIntegrator() {
252			currentSnapshot_->setChi(0.0);
253			currentSnapshot_->setIntegralOfChiDt(0.0);
254			}
255
256	tim	963	RealType NVT::calcConservedQuantity() {
257	gezelter	2
258	tim	963	RealType chi = currentSnapshot_->getChi();
259			RealType integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
260			RealType conservedQuantity;
261			RealType fkBT;
262			RealType Energy;
263			RealType thermostat_kinetic;
264			RealType thermostat_potential;
265	gezelter	246
266	gezelter	1390	fkBT = info_->getNdf() PhysicalConstants::kB targetTemp_;
267	gezelter	2
268	gezelter	246	Energy = thermo.getTotalE();
269	gezelter	2
270	gezelter	1390	thermostat_kinetic = fkBT * tauThermostat_ * tauThermostat_ * chi * chi / (2.0 * PhysicalConstants::energyConvert);
271	gezelter	2
272	gezelter	1390	thermostat_potential = fkBT * integralOfChidt / PhysicalConstants::energyConvert;
273	gezelter	2
274	gezelter	246	conservedQuantity = Energy + thermostat_kinetic + thermostat_potential;
275	gezelter	2
276	gezelter	246	return conservedQuantity;
277	gezelter	507	}
278	gezelter	2
279
280	gezelter	1390	}//end namespace OpenMD