ViewVC Help
View File | Revision Log | Show Annotations | View Changeset | Root Listing
root/group/trunk/OOPSE/libmdtools/NPTxyz.cpp
Revision: 812
Committed: Wed Oct 22 21:17:32 2003 UTC (20 years, 8 months ago) by mmeineke
File size: 6665 byte(s)
Log Message:
added a new NPT integrator, NPTxyz. It scales the x, y, and z direction sepeartely. no box skew allowed.

File Contents

# Content
1 #include <cmath>
2 #include "Atom.hpp"
3 #include "SRI.hpp"
4 #include "AbstractClasses.hpp"
5 #include "SimInfo.hpp"
6 #include "ForceFields.hpp"
7 #include "Thermo.hpp"
8 #include "ReadWrite.hpp"
9 #include "Integrator.hpp"
10 #include "simError.h"
11
12 #ifdef IS_MPI
13 #include "mpiSimulation.hpp"
14 #endif
15
16 // Basic non-isotropic thermostating and barostating via the Melchionna
17 // modification of the Hoover algorithm:
18 //
19 // Melchionna, S., Ciccotti, G., and Holian, B. L., 1993,
20 // Molec. Phys., 78, 533.
21 //
22 // and
23 //
24 // Hoover, W. G., 1986, Phys. Rev. A, 34, 2499.
25
26 template<typename T> NPTxyz<T>::NPTxyz ( SimInfo *theInfo, ForceFields* the_ff):
27 T( theInfo, the_ff )
28 {
29
30 int i,j;
31
32 for(i = 0; i < 3; i++){
33 for (j = 0; j < 3; j++){
34
35 eta[i][j] = 0.0;
36 oldEta[i][j] = 0.0;
37 }
38 }
39 }
40
41 template<typename T> NPTxyz<T>::~NPTxyz() {
42
43 // empty for now
44 }
45
46 template<typename T> void NPTxyz<T>::resetIntegrator() {
47
48 int i, j;
49
50 for(i = 0; i < 3; i++)
51 for (j = 0; j < 3; j++)
52 eta[i][j] = 0.0;
53
54 T::resetIntegrator();
55 }
56
57 template<typename T> void NPTxyz<T>::evolveEtaA() {
58
59 int i, j;
60
61 for(i = 0; i < 3; i ++){
62 for(j = 0; j < 3; j++){
63 if( i == j)
64 eta[i][j] += dt2 * instaVol *
65 (press[i][j] - targetPressure/p_convert) / (NkBT*tb2);
66 else
67 eta[i][j] = 0.0;
68 }
69 }
70
71 for(i = 0; i < 3; i++)
72 for (j = 0; j < 3; j++)
73 oldEta[i][j] = eta[i][j];
74 }
75
76 template<typename T> void NPTxyz<T>::evolveEtaB() {
77
78 int i,j;
79
80 for(i = 0; i < 3; i++)
81 for (j = 0; j < 3; j++)
82 prevEta[i][j] = eta[i][j];
83
84 for(i = 0; i < 3; i ++){
85 for(j = 0; j < 3; j++){
86 if( i == j) {
87 eta[i][j] = oldEta[i][j] + dt2 * instaVol *
88 (press[i][j] - targetPressure/p_convert) / (NkBT*tb2);
89 } else {
90 eta[i][j] = 0.0;
91 }
92 }
93 }
94 }
95
96 template<typename T> void NPTxyz<T>::getVelScaleA(double sc[3], double vel[3]) {
97 int i,j;
98 double vScale[3][3];
99
100 for (i = 0; i < 3; i++ ) {
101 for (j = 0; j < 3; j++ ) {
102 vScale[i][j] = eta[i][j];
103
104 if (i == j) {
105 vScale[i][j] += chi;
106 }
107 }
108 }
109
110 info->matVecMul3( vScale, vel, sc );
111 }
112
113 template<typename T> void NPTxyz<T>::getVelScaleB(double sc[3], int index ){
114 int i,j;
115 double myVel[3];
116 double vScale[3][3];
117
118 for (i = 0; i < 3; i++ ) {
119 for (j = 0; j < 3; j++ ) {
120 vScale[i][j] = eta[i][j];
121
122 if (i == j) {
123 vScale[i][j] += chi;
124 }
125 }
126 }
127
128 for (j = 0; j < 3; j++)
129 myVel[j] = oldVel[3*index + j];
130
131 info->matVecMul3( vScale, myVel, sc );
132 }
133
134 template<typename T> void NPTxyz<T>::getPosScale(double pos[3], double COM[3],
135 int index, double sc[3]){
136 int j;
137 double rj[3];
138
139 for(j=0; j<3; j++)
140 rj[j] = ( oldPos[index*3+j] + pos[j]) / 2.0 - COM[j];
141
142 info->matVecMul3( eta, rj, sc );
143 }
144
145 template<typename T> void NPTxyz<T>::scaleSimBox( void ){
146
147 int i,j,k;
148 double scaleMat[3][3];
149 double eta2ij, scaleFactor;
150 double bigScale, smallScale, offDiagMax;
151 double hm[3][3], hmnew[3][3];
152
153
154
155 // Scale the box after all the positions have been moved:
156
157 // Use a taylor expansion for eta products: Hmat = Hmat . exp(dt * etaMat)
158 // Hmat = Hmat . ( Ident + dt * etaMat + dt^2 * etaMat*etaMat / 2)
159
160 bigScale = 1.0;
161 smallScale = 1.0;
162 offDiagMax = 0.0;
163
164 for(i=0; i<3; i++){
165 for(j=0; j<3; j++){
166 scaleMat[i][j] = 0.0;
167 if(i==j) scaleMat[i][j] = 1.0;
168 }
169 }
170
171 for(i=0;i<3;i++){
172
173 // calculate the scaleFactors
174
175 scaleFactor = exp(dt*eta[i][i]);
176
177 scaleMat[i][i] = scaleFactor;
178
179 if (scaleMat[i][i] > bigScale) bigScale = scaleMat[i][i];
180 if (scaleMat[i][i] < smallScale) smallScale = scaleMat[i][i];
181 }
182
183 // for(i=0; i<3; i++){
184 // for(j=0; j<3; j++){
185
186 // // Calculate the matrix Product of the eta array (we only need
187 // // the ij element right now):
188
189 // eta2ij = 0.0;
190 // for(k=0; k<3; k++){
191 // eta2ij += eta[i][k] * eta[k][j];
192 // }
193
194 // scaleMat[i][j] = 0.0;
195 // // identity matrix (see above):
196 // if (i == j) scaleMat[i][j] = 1.0;
197 // // Taylor expansion for the exponential truncated at second order:
198 // scaleMat[i][j] += dt*eta[i][j] + 0.5*dt*dt*eta2ij;
199
200 // if (i != j)
201 // if (fabs(scaleMat[i][j]) > offDiagMax)
202 // offDiagMax = fabs(scaleMat[i][j]);
203 // }
204
205 // if (scaleMat[i][i] > bigScale) bigScale = scaleMat[i][i];
206 // if (scaleMat[i][i] < smallScale) smallScale = scaleMat[i][i];
207 // }
208
209 if ((bigScale > 1.1) || (smallScale < 0.9)) {
210 sprintf( painCave.errMsg,
211 "NPTxyz error: Attempting a Box scaling of more than 10 percent.\n"
212 " Check your tauBarostat, as it is probably too small!\n\n"
213 " scaleMat = [%lf\t%lf\t%lf]\n"
214 " [%lf\t%lf\t%lf]\n"
215 " [%lf\t%lf\t%lf]\n",
216 scaleMat[0][0],scaleMat[0][1],scaleMat[0][2],
217 scaleMat[1][0],scaleMat[1][1],scaleMat[1][2],
218 scaleMat[2][0],scaleMat[2][1],scaleMat[2][2]);
219 painCave.isFatal = 1;
220 simError();
221 } else {
222 info->getBoxM(hm);
223 info->matMul3(hm, scaleMat, hmnew);
224 info->setBoxM(hmnew);
225 }
226 }
227
228 template<typename T> bool NPTxyz<T>::etaConverged() {
229 int i;
230 double diffEta, sumEta;
231
232 sumEta = 0;
233 for(i = 0; i < 3; i++)
234 sumEta += pow(prevEta[i][i] - eta[i][i], 2);
235
236 diffEta = sqrt( sumEta / 3.0 );
237
238 return ( diffEta <= etaTolerance );
239 }
240
241 template<typename T> double NPTxyz<T>::getConservedQuantity(void){
242
243 double conservedQuantity;
244 double totalEnergy;
245 double thermostat_kinetic;
246 double thermostat_potential;
247 double barostat_kinetic;
248 double barostat_potential;
249 double trEta;
250 double a[3][3], b[3][3];
251
252 totalEnergy = tStats->getTotalE();
253
254 thermostat_kinetic = fkBT * tt2 * chi * chi /
255 (2.0 * eConvert);
256
257 thermostat_potential = fkBT* integralOfChidt / eConvert;
258
259 info->transposeMat3(eta, a);
260 info->matMul3(a, eta, b);
261 trEta = info->matTrace3(b);
262
263 barostat_kinetic = NkBT * tb2 * trEta /
264 (2.0 * eConvert);
265
266 barostat_potential = (targetPressure * tStats->getVolume() / p_convert) /
267 eConvert;
268
269 conservedQuantity = totalEnergy + thermostat_kinetic + thermostat_potential +
270 barostat_kinetic + barostat_potential;
271
272 // cout.width(8);
273 // cout.precision(8);
274
275 // cerr << info->getTime() << "\t" << Energy << "\t" << thermostat_kinetic <<
276 // "\t" << thermostat_potential << "\t" << barostat_kinetic <<
277 // "\t" << barostat_potential << "\t" << conservedQuantity << endl;
278
279 return conservedQuantity;
280
281 }