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root/OpenMD/branches/development/src/integrators/NPTxyz.cpp
Revision: 1629
Committed: Wed Sep 14 21:15:17 2011 UTC (13 years, 7 months ago) by gezelter
File size: 5929 byte(s)
Log Message:
Merging changes from old branch into development branch

File Contents

# 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 tim 3 #include "brains/SimInfo.hpp"
43     #include "brains/Thermo.hpp"
44 gezelter 246 #include "integrators/IntegratorCreator.hpp"
45     #include "integrators/NPTxyz.hpp"
46     #include "primitives/Molecule.hpp"
47 gezelter 1390 #include "utils/PhysicalConstants.hpp"
48 tim 3 #include "utils/simError.h"
49 gezelter 2
50     // Basic non-isotropic thermostating and barostating via the Melchionna
51     // modification of the Hoover algorithm:
52     //
53     // Melchionna, S., Ciccotti, G., and Holian, B. L., 1993,
54     // Molec. Phys., 78, 533.
55     //
56     // and
57     //
58     // Hoover, W. G., 1986, Phys. Rev. A, 34, 2499.
59    
60 gezelter 1390 namespace OpenMD {
61 gezelter 2
62 gezelter 246
63 tim 963 RealType NPTxyz::calcConservedQuantity(){
64 gezelter 2
65 gezelter 1629 chi= currentSnapshot_->getChi();
66     integralOfChidt = currentSnapshot_->getIntegralOfChiDt();
67     loadEta();
68    
69 gezelter 246 // We need NkBT a lot, so just set it here: This is the RAW number
70     // of integrableObjects, so no subtraction or addition of constraints or
71     // orientational degrees of freedom:
72 gezelter 1390 NkBT = info_->getNGlobalIntegrableObjects()*PhysicalConstants::kB *targetTemp;
73 gezelter 2
74 gezelter 246 // fkBT is used because the thermostat operates on more degrees of freedom
75     // than the barostat (when there are particles with orientational degrees
76     // of freedom).
77 gezelter 1390 fkBT = info_->getNdf()*PhysicalConstants::kB *targetTemp;
78 gezelter 2
79 tim 963 RealType conservedQuantity;
80     RealType totalEnergy;
81     RealType thermostat_kinetic;
82     RealType thermostat_potential;
83     RealType barostat_kinetic;
84     RealType barostat_potential;
85     RealType trEta;
86 gezelter 2
87 gezelter 246 totalEnergy = thermo.getTotalE();
88 gezelter 2
89 gezelter 1390 thermostat_kinetic = fkBT * tt2 * chi * chi /(2.0 * PhysicalConstants::energyConvert);
90 gezelter 2
91 gezelter 1390 thermostat_potential = fkBT* integralOfChidt / PhysicalConstants::energyConvert;
92 gezelter 2
93 tim 963 SquareMatrix<RealType, 3> tmp = eta.transpose() * eta;
94 gezelter 246 trEta = tmp.trace();
95 gezelter 2
96 gezelter 1390 barostat_kinetic = NkBT * tb2 * trEta /(2.0 * PhysicalConstants::energyConvert);
97 gezelter 2
98 gezelter 1390 barostat_potential = (targetPressure * thermo.getVolume() / PhysicalConstants::pressureConvert) /PhysicalConstants::energyConvert;
99 gezelter 2
100 gezelter 246 conservedQuantity = totalEnergy + thermostat_kinetic + thermostat_potential +
101 gezelter 507 barostat_kinetic + barostat_potential;
102 gezelter 2
103    
104 gezelter 246 return conservedQuantity;
105 gezelter 2
106 gezelter 507 }
107 gezelter 2
108 gezelter 246
109 gezelter 507 void NPTxyz::scaleSimBox(){
110 gezelter 2
111 gezelter 246 int i,j,k;
112     Mat3x3d scaleMat;
113 tim 963 RealType eta2ij, scaleFactor;
114     RealType bigScale, smallScale, offDiagMax;
115 gezelter 246 Mat3x3d hm;
116     Mat3x3d hmnew;
117 gezelter 2
118    
119    
120 gezelter 507 // Scale the box after all the positions have been moved:
121 gezelter 2
122 gezelter 507 // Use a taylor expansion for eta products: Hmat = Hmat . exp(dt * etaMat)
123     // Hmat = Hmat . ( Ident + dt * etaMat + dt^2 * etaMat*etaMat / 2)
124 gezelter 2
125 gezelter 246 bigScale = 1.0;
126     smallScale = 1.0;
127     offDiagMax = 0.0;
128 gezelter 2
129 gezelter 246 for(i=0; i<3; i++){
130 gezelter 507 for(j=0; j<3; j++){
131     scaleMat(i, j) = 0.0;
132     if(i==j) {
133     scaleMat(i, j) = 1.0;
134     }
135     }
136 gezelter 2 }
137    
138 gezelter 246 for(i=0;i<3;i++){
139 gezelter 2
140 gezelter 507 // calculate the scaleFactors
141 gezelter 2
142 gezelter 507 scaleFactor = exp(dt*eta(i, i));
143 gezelter 2
144 gezelter 507 scaleMat(i, i) = scaleFactor;
145 gezelter 2
146 gezelter 507 if (scaleMat(i, i) > bigScale) {
147     bigScale = scaleMat(i, i);
148     }
149 gezelter 246
150 gezelter 507 if (scaleMat(i, i) < smallScale) {
151     smallScale = scaleMat(i, i);
152     }
153 gezelter 246 }
154 gezelter 2
155 gezelter 246 if ((bigScale > 1.1) || (smallScale < 0.9)) {
156 gezelter 507 sprintf( painCave.errMsg,
157     "NPTxyz error: Attempting a Box scaling of more than 10 percent.\n"
158     " Check your tauBarostat, as it is probably too small!\n\n"
159     " scaleMat = [%lf\t%lf\t%lf]\n"
160     " [%lf\t%lf\t%lf]\n"
161     " [%lf\t%lf\t%lf]\n",
162     scaleMat(0, 0),scaleMat(0, 1),scaleMat(0, 2),
163     scaleMat(1, 0),scaleMat(1, 1),scaleMat(1, 2),
164     scaleMat(2, 0),scaleMat(2, 1),scaleMat(2, 2));
165     painCave.isFatal = 1;
166     simError();
167 gezelter 246 } else {
168 gezelter 2
169 gezelter 507 Mat3x3d hmat = currentSnapshot_->getHmat();
170     hmat = hmat *scaleMat;
171     currentSnapshot_->setHmat(hmat);
172 gezelter 246 }
173 gezelter 507 }
174 gezelter 2
175 gezelter 507 void NPTxyz::loadEta() {
176 gezelter 246 eta= currentSnapshot_->getEta();
177 gezelter 507 }
178 gezelter 2
179     }

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