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root/OpenMD/branches/development/src/nonbonded/GB.cpp
Revision: 1483
Committed: Tue Jul 27 21:17:31 2010 UTC (14 years, 9 months ago) by gezelter
File size: 13619 byte(s)
Log Message:
Added GB module to the C++ side, got rid of it on the fortran side.

File Contents

# Content
1 /*
2 * 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 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * 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 *
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 */
41
42 #include <stdio.h>
43 #include <string.h>
44
45 #include <cmath>
46 #include "nonbonded/GB.hpp"
47 #include "nonbonded/LJ.hpp"
48 #include "utils/simError.h"
49
50 using namespace std;
51 namespace OpenMD {
52
53 bool GB::initialized_ = false;
54 RealType GB::mu_ = 2.0;
55 RealType GB::nu_ = 1.0;
56 ForceField* GB::forceField_ = NULL;
57 map<int, AtomType*> GB::GBMap;
58 map<pair<AtomType*, AtomType*>, GBInteractionData> GB::MixingMap;
59
60 GB* GB::_instance = NULL;
61
62 GB* GB::Instance() {
63 if (!_instance) {
64 _instance = new GB();
65 }
66 return _instance;
67 }
68
69 GayBerneParam GB::getGayBerneParam(AtomType* atomType) {
70
71 // Do sanity checking on the AtomType we were passed before
72 // building any data structures:
73 if (!atomType->isGayBerne()) {
74 sprintf( painCave.errMsg,
75 "GB::getGayBerneParam was passed an atomType (%s) that does\n"
76 "\tnot appear to be a Gay-Berne atom.\n",
77 atomType->getName().c_str());
78 painCave.severity = OPENMD_ERROR;
79 painCave.isFatal = 1;
80 simError();
81 }
82
83 DirectionalAtomType* daType = dynamic_cast<DirectionalAtomType*>(atomType);
84 GenericData* data = daType->getPropertyByName("GayBerne");
85 if (data == NULL) {
86 sprintf( painCave.errMsg, "GB::getGayBerneParam could not find\n"
87 "\tGay-Berne parameters for atomType %s.\n",
88 daType->getName().c_str());
89 painCave.severity = OPENMD_ERROR;
90 painCave.isFatal = 1;
91 simError();
92 }
93
94 GayBerneParamGenericData* gbData = dynamic_cast<GayBerneParamGenericData*>(data);
95 if (gbData == NULL) {
96 sprintf( painCave.errMsg,
97 "GB::getGayBerneParam could not convert GenericData to\n"
98 "\tGayBerneParamGenericData for atom type %s\n",
99 daType->getName().c_str());
100 painCave.severity = OPENMD_ERROR;
101 painCave.isFatal = 1;
102 simError();
103 }
104
105 return gbData->getData();
106 }
107
108 void GB::initialize() {
109 ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes();
110 ForceField::AtomTypeContainer::MapTypeIterator i;
111 AtomType* at;
112
113 // GB handles all of the GB-GB interactions as well as GB-LJ cross
114 // interactions:
115
116 for (at = atomTypes->beginType(i); at != NULL;
117 at = atomTypes->nextType(i)) {
118
119 if (at->isGayBerne() || at->isLennardJones())
120 addType(at);
121 }
122
123 initialized_ = true;
124 }
125
126 void GB::addType(AtomType* atomType){
127 // add it to the map:
128 AtomTypeProperties atp = atomType->getATP();
129
130 pair<map<int,AtomType*>::iterator,bool> ret;
131 ret = GBMap.insert( pair<int, AtomType*>(atp.ident, atomType) );
132 if (ret.second == false) {
133 sprintf( painCave.errMsg,
134 "GB already had a previous entry with ident %d\n",
135 atp.ident);
136 painCave.severity = OPENMD_INFO;
137 painCave.isFatal = 0;
138 simError();
139 }
140
141 RealType d1, l1, e1, er1, dw1;
142
143 if (atomType->isGayBerne()) {
144 GayBerneParam gb1 = getGayBerneParam(atomType);
145 d1 = gb1.GB_d;
146 l1 = gb1.GB_l;
147 e1 = gb1.GB_eps;
148 er1 = gb1.GB_eps_ratio;
149 dw1 = gb1.GB_dw;
150 } else if (atomType->isLennardJones()) {
151 d1 = LJ::Instance()->getSigma(atomType) / sqrt(2.0);
152 e1 = LJ::Instance()->getEpsilon(atomType);
153 l1 = d1;
154 er1 = 1.0;
155 dw1 = 1.0;
156 } else {
157 sprintf( painCave.errMsg,
158 "GB::addType was passed an atomType (%s) that does not\n"
159 "\tappear to be a Gay-Berne or Lennard-Jones atom.\n",
160 atomType->getName().c_str());
161 painCave.severity = OPENMD_ERROR;
162 painCave.isFatal = 1;
163 simError();
164 }
165
166
167 // Now, iterate over all known types and add to the mixing map:
168
169 map<int, AtomType*>::iterator it;
170 for( it = GBMap.begin(); it != GBMap.end(); ++it) {
171
172 AtomType* atype2 = (*it).second;
173
174 RealType d2, l2, e2, er2, dw2;
175
176 if (atype2->isGayBerne()) {
177 GayBerneParam gb2 = getGayBerneParam(atype2);
178 d2 = gb2.GB_d;
179 l2 = gb2.GB_l;
180 e2 = gb2.GB_eps;
181 er2 = gb2.GB_eps_ratio;
182 dw2 = gb2.GB_dw;
183 } else if (atype2->isLennardJones()) {
184 d2 = LJ::Instance()->getSigma(atype2) / sqrt(2.0);
185 e2 = LJ::Instance()->getEpsilon(atype2);
186 l2 = d2;
187 er2 = 1.0;
188 dw2 = 1.0;
189 }
190
191 GBInteractionData mixer;
192
193 // Cleaver paper uses sqrt of squares to get sigma0 for
194 // mixed interactions.
195
196 mixer.sigma0 = sqrt(d1*d1 + d2*d2);
197 mixer.xa2 = (l1*l1 - d1*d1)/(l1*l1 + d2*d2);
198 mixer.xai2 = (l2*l2 - d2*d2)/(l2*l2 + d1*d1);
199 mixer.x2 = (l1*l1 - d1*d1) * (l2*l2 - d2*d2) /
200 ((l2*l2 + d1*d1) * (l1*l1 + d2*d2));
201
202 // assumed LB mixing rules for now:
203
204 mixer.dw = 0.5 * (dw1 + dw2);
205 mixer.eps0 = sqrt(e1 * e2);
206
207 RealType er = sqrt(er1 * er2);
208 RealType ermu = pow(er,(1.0 / mu_));
209 RealType xp = (1.0 - ermu) / (1.0 + ermu);
210 RealType ap2 = 1.0 / (1.0 + ermu);
211
212 mixer.xp2 = xp * xp;
213 mixer.xpap2 = xp * ap2;
214 mixer.xpapi2 = xp / ap2;
215
216 // only add this pairing if at least one of the atoms is a Gay-Berne atom
217
218 if (atomType->isGayBerne() || atype2->isGayBerne()) {
219
220 pair<AtomType*, AtomType*> key1, key2;
221 key1 = make_pair(atomType, atype2);
222 key2 = make_pair(atype2, atomType);
223
224 MixingMap[key1] = mixer;
225 if (key2 != key1) {
226 MixingMap[key2] = mixer;
227 }
228 }
229 }
230 }
231
232
233 RealType GB::getGayBerneCut(int atid) {
234 if (!initialized_) initialize();
235 std::map<int, AtomType*> :: const_iterator it;
236 it = GBMap.find(atid);
237 if (it == GBMap.end()) {
238 sprintf( painCave.errMsg,
239 "GB::getGayBerneCut could not find atid %d in GBMap\n",
240 (atid));
241 painCave.severity = OPENMD_ERROR;
242 painCave.isFatal = 1;
243 simError();
244 }
245
246 AtomType* atype = it->second;
247
248 RealType gbCut;
249
250 if (atype->isGayBerne()) {
251 GayBerneParam gb = getGayBerneParam(atype);
252
253 // sigma is actually sqrt(2) * l for prolate ellipsoids
254 gbCut = 2.5 * sqrt(2.0) * max(gb.GB_l, gb.GB_d);
255
256 } else if (atype->isLennardJones()) {
257 gbCut = 2.5 * LJ::Instance()->getSigma(atype);
258 }
259
260 return gbCut;
261 }
262
263
264 void GB::calcForce(AtomType* at1, AtomType* at2, Vector3d d,
265 RealType r, RealType r2, RealType sw,
266 RealType vdwMult, RealType &vpair, RealType &pot,
267 RotMat3x3d A1, RotMat3x3d A2, Vector3d &f1,
268 Vector3d &t1, Vector3d &t2) {
269
270 if (!initialized_) initialize();
271
272 pair<AtomType*, AtomType*> key = make_pair(at1, at2);
273 GBInteractionData mixer = MixingMap[key];
274
275 RealType sigma0 = mixer.sigma0;
276 RealType dw = mixer.dw;
277 RealType eps0 = mixer.eps0;
278 RealType x2 = mixer.x2;
279 RealType xa2 = mixer.xa2;
280 RealType xai2 = mixer.xai2;
281 RealType xp2 = mixer.xp2;
282 RealType xpap2 = mixer.xpap2;
283 RealType xpapi2 = mixer.xpapi2;
284
285 Vector3d ul1 = A1.getColumn(2);
286 Vector3d ul2 = A2.getColumn(2);
287
288 RealType a, b, g;
289
290 bool i_is_LJ = at1->isLennardJones();
291 bool j_is_LJ = at2->isLennardJones();
292
293 if (i_is_LJ) {
294 a = 0.0;
295 ul1 = V3Zero;
296 } else {
297 a = dot(d, ul1);
298 }
299
300 if (j_is_LJ) {
301 b = 0.0;
302 ul2 = V3Zero;
303 } else {
304 b = dot(d, ul2);
305 }
306
307 if (i_is_LJ || j_is_LJ)
308 g = 0.0;
309 else
310 g = dot(ul1, ul2);
311
312 RealType au = a / r;
313 RealType bu = b / r;
314
315 RealType au2 = au * au;
316 RealType bu2 = bu * bu;
317 RealType g2 = g * g;
318
319 RealType H = (xa2 * au2 + xai2 * bu2 - 2.0*x2*au*bu*g) / (1.0 - x2*g2);
320 RealType Hp = (xpap2*au2 + xpapi2*bu2 - 2.0*xp2*au*bu*g) / (1.0 - xp2*g2);
321
322 RealType sigma = sigma0 / sqrt(1.0 - H);
323 RealType e1 = 1.0 / sqrt(1.0 - x2*g2);
324 RealType e2 = 1.0 - Hp;
325 RealType eps = eps0 * pow(e1,nu_) * pow(e2,mu_);
326 RealType BigR = dw*sigma0 / (r - sigma + dw*sigma0);
327
328 RealType R3 = BigR*BigR*BigR;
329 RealType R6 = R3*R3;
330 RealType R7 = R6 * BigR;
331 RealType R12 = R6*R6;
332 RealType R13 = R6*R7;
333
334 RealType U = vdwMult * 4.0 * eps * (R12 - R6);
335
336 RealType s3 = sigma*sigma*sigma;
337 RealType s03 = sigma0*sigma0*sigma0;
338
339 RealType pref1 = - vdwMult * 8.0 * eps * mu_ * (R12 - R6) / (e2 * r);
340
341 RealType pref2 = vdwMult * 8.0 * eps * s3 * (6.0*R13 - 3.0*R7) /(dw*r*s03);
342
343 RealType dUdr = - (pref1 * Hp + pref2 * (sigma0*sigma0*r/s3 + H));
344
345 RealType dUda = pref1 * (xpap2*au - xp2*bu*g) / (1.0 - xp2 * g2)
346 + pref2 * (xa2 * au - x2 *bu*g) / (1.0 - x2 * g2);
347
348 RealType dUdb = pref1 * (xpapi2*bu - xp2*au*g) / (1.0 - xp2 * g2)
349 + pref2 * (xai2 * bu - x2 *au*g) / (1.0 - x2 * g2);
350
351 RealType dUdg = 4.0 * eps * nu_ * (R12 - R6) * x2 * g / (1.0 - x2*g2)
352 + 8.0 * eps * mu_ * (R12 - R6) * (xp2*au*bu - Hp*xp2*g) /
353 (1.0 - xp2 * g2) / e2 + 8.0 * eps * s3 * (3.0 * R7 - 6.0 * R13) *
354 (x2 * au * bu - H * x2 * g) / (1.0 - x2 * g2) / (dw * s03);
355
356
357 Vector3d rhat = d / r;
358 Vector3d rxu1 = cross(d, ul1);
359 Vector3d rxu2 = cross(d, ul2);
360 Vector3d uxu = cross(ul1, ul2);
361
362 pot += U*sw;
363 f1 += dUdr * rhat + dUda * ul1 + dUdb * ul2;
364 t1 += dUda * rxu1 - dUdg * uxu;
365 t2 += dUdb * rxu2 - dUdg * uxu;
366 vpair += U*sw;
367
368 return;
369
370 }
371
372 void GB::do_gb_pair(int *atid1, int *atid2, RealType *d, RealType *r,
373 RealType *r2, RealType *sw, RealType *vdwMult,
374 RealType *vpair, RealType *pot, RealType *A1,
375 RealType *A2, RealType *f1, RealType *t1, RealType *t2) {
376
377 if (!initialized_) initialize();
378
379 AtomType* atype1 = GBMap[*atid1];
380 AtomType* atype2 = GBMap[*atid2];
381
382 Vector3d disp(d);
383 Vector3d frc(f1);
384 Vector3d trq1(t1);
385 Vector3d trq2(t2);
386 RotMat3x3d Ai(A1);
387 RotMat3x3d Aj(A2);
388
389 // Fortran has the opposite matrix ordering from c++, so we'll use
390 // transpose here. When we finish the conversion to C++, this wrapper
391 // will disappear, as will the transpose below:
392
393 calcForce(atype1, atype2, disp, *r, *r2, *sw, *vdwMult, *vpair, *pot,
394 Ai.transpose(), Aj.transpose(), frc, trq1, trq1);
395
396 f1[0] = frc.x();
397 f1[1] = frc.y();
398 f1[2] = frc.z();
399
400 t1[0] = trq1.x();
401 t1[1] = trq1.y();
402 t1[2] = trq1.z();
403
404 t2[0] = trq2.x();
405 t2[1] = trq2.y();
406 t2[2] = trq2.z();
407
408 return;
409 }
410 }
411
412 extern "C" {
413
414 #define fortranGetGayBerneCut FC_FUNC(getgaybernecut, GETGAYBERNECUT)
415 #define fortranDoGBPair FC_FUNC(do_gb_pair, DO_GB_PAIR)
416
417 RealType fortranGetGayBerneCut(int* atid) {
418 return OpenMD::GB::Instance()->getGayBerneCut(*atid);
419 }
420
421 void fortranDoGBPair(int *atid1, int *atid2, RealType *d, RealType *r,
422 RealType *r2, RealType *sw, RealType *vdwMult,
423 RealType *vpair, RealType *pot, RealType *A1,
424 RealType *A2, RealType *f1, RealType *t1, RealType *t2){
425
426 return OpenMD::GB::Instance()->do_gb_pair(atid1, atid2, d, r, r2, sw,
427 vdwMult, vpair, pot, A1, A2, f1,
428 t1, t2);
429 }
430 }

Properties

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