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root/OpenMD/branches/development/src/nonbonded/GB.cpp
Revision: 1485
Committed: Wed Jul 28 19:52:00 2010 UTC (14 years, 9 months ago) by gezelter
File size: 13724 byte(s)
Log Message:
Converting Sticky over to C++

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
110 ForceFieldOptions& fopts = forceField_->getForceFieldOptions();
111 mu_ = fopts.getGayBerneMu();
112 nu_ = fopts.getGayBerneNu();
113 ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes();
114 ForceField::AtomTypeContainer::MapTypeIterator i;
115 AtomType* at;
116
117 // GB handles all of the GB-GB interactions as well as GB-LJ cross
118 // interactions:
119
120 for (at = atomTypes->beginType(i); at != NULL;
121 at = atomTypes->nextType(i)) {
122
123 if (at->isGayBerne() || at->isLennardJones())
124 addType(at);
125 }
126
127 initialized_ = true;
128 }
129
130 void GB::addType(AtomType* atomType){
131 // add it to the map:
132 AtomTypeProperties atp = atomType->getATP();
133
134 pair<map<int,AtomType*>::iterator,bool> ret;
135 ret = GBMap.insert( pair<int, AtomType*>(atp.ident, atomType) );
136 if (ret.second == false) {
137 sprintf( painCave.errMsg,
138 "GB already had a previous entry with ident %d\n",
139 atp.ident);
140 painCave.severity = OPENMD_INFO;
141 painCave.isFatal = 0;
142 simError();
143 }
144
145 RealType d1, l1, e1, er1, dw1;
146
147 if (atomType->isGayBerne()) {
148 GayBerneParam gb1 = getGayBerneParam(atomType);
149 d1 = gb1.GB_d;
150 l1 = gb1.GB_l;
151 e1 = gb1.GB_eps;
152 er1 = gb1.GB_eps_ratio;
153 dw1 = gb1.GB_dw;
154 } else if (atomType->isLennardJones()) {
155 d1 = LJ::Instance()->getSigma(atomType) / sqrt(2.0);
156 e1 = LJ::Instance()->getEpsilon(atomType);
157 l1 = d1;
158 er1 = 1.0;
159 dw1 = 1.0;
160 } else {
161 sprintf( painCave.errMsg,
162 "GB::addType was passed an atomType (%s) that does not\n"
163 "\tappear to be a Gay-Berne or Lennard-Jones atom.\n",
164 atomType->getName().c_str());
165 painCave.severity = OPENMD_ERROR;
166 painCave.isFatal = 1;
167 simError();
168 }
169
170
171 // Now, iterate over all known types and add to the mixing map:
172
173 map<int, AtomType*>::iterator it;
174 for( it = GBMap.begin(); it != GBMap.end(); ++it) {
175
176 AtomType* atype2 = (*it).second;
177
178 RealType d2, l2, e2, er2, dw2;
179
180 if (atype2->isGayBerne()) {
181 GayBerneParam gb2 = getGayBerneParam(atype2);
182 d2 = gb2.GB_d;
183 l2 = gb2.GB_l;
184 e2 = gb2.GB_eps;
185 er2 = gb2.GB_eps_ratio;
186 dw2 = gb2.GB_dw;
187 } else if (atype2->isLennardJones()) {
188 d2 = LJ::Instance()->getSigma(atype2) / sqrt(2.0);
189 e2 = LJ::Instance()->getEpsilon(atype2);
190 l2 = d2;
191 er2 = 1.0;
192 dw2 = 1.0;
193 }
194
195 GBInteractionData mixer;
196
197 // Cleaver paper uses sqrt of squares to get sigma0 for
198 // mixed interactions.
199
200 mixer.sigma0 = sqrt(d1*d1 + d2*d2);
201 mixer.xa2 = (l1*l1 - d1*d1)/(l1*l1 + d2*d2);
202 mixer.xai2 = (l2*l2 - d2*d2)/(l2*l2 + d1*d1);
203 mixer.x2 = (l1*l1 - d1*d1) * (l2*l2 - d2*d2) /
204 ((l2*l2 + d1*d1) * (l1*l1 + d2*d2));
205
206 // assumed LB mixing rules for now:
207
208 mixer.dw = 0.5 * (dw1 + dw2);
209 mixer.eps0 = sqrt(e1 * e2);
210
211 RealType er = sqrt(er1 * er2);
212 RealType ermu = pow(er,(1.0 / mu_));
213 RealType xp = (1.0 - ermu) / (1.0 + ermu);
214 RealType ap2 = 1.0 / (1.0 + ermu);
215
216 mixer.xp2 = xp * xp;
217 mixer.xpap2 = xp * ap2;
218 mixer.xpapi2 = xp / ap2;
219
220 // only add this pairing if at least one of the atoms is a Gay-Berne atom
221
222 if (atomType->isGayBerne() || atype2->isGayBerne()) {
223
224 pair<AtomType*, AtomType*> key1, key2;
225 key1 = make_pair(atomType, atype2);
226 key2 = make_pair(atype2, atomType);
227
228 MixingMap[key1] = mixer;
229 if (key2 != key1) {
230 MixingMap[key2] = mixer;
231 }
232 }
233 }
234 }
235
236
237 RealType GB::getGayBerneCut(int atid) {
238 if (!initialized_) initialize();
239 std::map<int, AtomType*> :: const_iterator it;
240 it = GBMap.find(atid);
241 if (it == GBMap.end()) {
242 sprintf( painCave.errMsg,
243 "GB::getGayBerneCut could not find atid %d in GBMap\n",
244 (atid));
245 painCave.severity = OPENMD_ERROR;
246 painCave.isFatal = 1;
247 simError();
248 }
249
250 AtomType* atype = it->second;
251
252 RealType gbCut;
253
254 if (atype->isGayBerne()) {
255 GayBerneParam gb = getGayBerneParam(atype);
256
257 // sigma is actually sqrt(2) * l for prolate ellipsoids
258 gbCut = 2.5 * sqrt(2.0) * max(gb.GB_l, gb.GB_d);
259
260 } else if (atype->isLennardJones()) {
261 gbCut = 2.5 * LJ::Instance()->getSigma(atype);
262 }
263
264 return gbCut;
265 }
266
267
268 void GB::calcForce(AtomType* at1, AtomType* at2, Vector3d d,
269 RealType r, RealType r2, RealType sw,
270 RealType vdwMult, RealType &vpair, RealType &pot,
271 RotMat3x3d A1, RotMat3x3d A2, Vector3d &f1,
272 Vector3d &t1, Vector3d &t2) {
273
274 if (!initialized_) initialize();
275
276 pair<AtomType*, AtomType*> key = make_pair(at1, at2);
277 GBInteractionData mixer = MixingMap[key];
278
279 RealType sigma0 = mixer.sigma0;
280 RealType dw = mixer.dw;
281 RealType eps0 = mixer.eps0;
282 RealType x2 = mixer.x2;
283 RealType xa2 = mixer.xa2;
284 RealType xai2 = mixer.xai2;
285 RealType xp2 = mixer.xp2;
286 RealType xpap2 = mixer.xpap2;
287 RealType xpapi2 = mixer.xpapi2;
288
289 Vector3d ul1 = A1.getRow(2);
290 Vector3d ul2 = A2.getRow(2);
291
292 RealType a, b, g;
293
294 bool i_is_LJ = at1->isLennardJones();
295 bool j_is_LJ = at2->isLennardJones();
296
297 if (i_is_LJ) {
298 a = 0.0;
299 ul1 = V3Zero;
300 } else {
301 a = dot(d, ul1);
302 }
303
304 if (j_is_LJ) {
305 b = 0.0;
306 ul2 = V3Zero;
307 } else {
308 b = dot(d, ul2);
309 }
310
311 if (i_is_LJ || j_is_LJ)
312 g = 0.0;
313 else
314 g = dot(ul1, ul2);
315
316 RealType au = a / r;
317 RealType bu = b / r;
318
319 RealType au2 = au * au;
320 RealType bu2 = bu * bu;
321 RealType g2 = g * g;
322
323 RealType H = (xa2 * au2 + xai2 * bu2 - 2.0*x2*au*bu*g) / (1.0 - x2*g2);
324 RealType Hp = (xpap2*au2 + xpapi2*bu2 - 2.0*xp2*au*bu*g) / (1.0 - xp2*g2);
325
326 RealType sigma = sigma0 / sqrt(1.0 - H);
327 RealType e1 = 1.0 / sqrt(1.0 - x2*g2);
328 RealType e2 = 1.0 - Hp;
329 RealType eps = eps0 * pow(e1,nu_) * pow(e2,mu_);
330 RealType BigR = dw*sigma0 / (r - sigma + dw*sigma0);
331
332 RealType R3 = BigR*BigR*BigR;
333 RealType R6 = R3*R3;
334 RealType R7 = R6 * BigR;
335 RealType R12 = R6*R6;
336 RealType R13 = R6*R7;
337
338 RealType U = vdwMult * 4.0 * eps * (R12 - R6);
339
340 RealType s3 = sigma*sigma*sigma;
341 RealType s03 = sigma0*sigma0*sigma0;
342
343 RealType pref1 = - vdwMult * 8.0 * eps * mu_ * (R12 - R6) / (e2 * r);
344
345 RealType pref2 = vdwMult * 8.0 * eps * s3 * (6.0*R13 - 3.0*R7) /(dw*r*s03);
346
347 RealType dUdr = - (pref1 * Hp + pref2 * (sigma0*sigma0*r/s3 + H));
348
349 RealType dUda = pref1 * (xpap2*au - xp2*bu*g) / (1.0 - xp2 * g2)
350 + pref2 * (xa2 * au - x2 *bu*g) / (1.0 - x2 * g2);
351
352 RealType dUdb = pref1 * (xpapi2*bu - xp2*au*g) / (1.0 - xp2 * g2)
353 + pref2 * (xai2 * bu - x2 *au*g) / (1.0 - x2 * g2);
354
355 RealType dUdg = 4.0 * eps * nu_ * (R12 - R6) * x2 * g / (1.0 - x2*g2)
356 + 8.0 * eps * mu_ * (R12 - R6) * (xp2*au*bu - Hp*xp2*g) /
357 (1.0 - xp2 * g2) / e2 + 8.0 * eps * s3 * (3.0 * R7 - 6.0 * R13) *
358 (x2 * au * bu - H * x2 * g) / (1.0 - x2 * g2) / (dw * s03);
359
360
361 Vector3d rhat = d / r;
362 Vector3d rxu1 = cross(d, ul1);
363 Vector3d rxu2 = cross(d, ul2);
364 Vector3d uxu = cross(ul1, ul2);
365
366 pot += U*sw;
367 f1 += dUdr * rhat + dUda * ul1 + dUdb * ul2;
368 t1 += dUda * rxu1 - dUdg * uxu;
369 t2 += dUdb * rxu2 - dUdg * uxu;
370 vpair += U*sw;
371
372 return;
373
374 }
375
376 void GB::do_gb_pair(int *atid1, int *atid2, RealType *d, RealType *r,
377 RealType *r2, RealType *sw, RealType *vdwMult,
378 RealType *vpair, RealType *pot, RealType *A1,
379 RealType *A2, RealType *f1, RealType *t1, RealType *t2) {
380
381 if (!initialized_) initialize();
382
383 AtomType* atype1 = GBMap[*atid1];
384 AtomType* atype2 = GBMap[*atid2];
385
386 Vector3d disp(d);
387 Vector3d frc(f1);
388 Vector3d trq1(t1);
389 Vector3d trq2(t2);
390 RotMat3x3d Ai(A1);
391 RotMat3x3d Aj(A2);
392
393 // Fortran has the opposite matrix ordering from c++, so we'll use
394 // transpose here. When we finish the conversion to C++, this wrapper
395 // will disappear, as will the transpose below:
396
397 calcForce(atype1, atype2, disp, *r, *r2, *sw, *vdwMult, *vpair, *pot,
398 Ai, Aj, frc, trq1, trq1);
399
400 f1[0] = frc.x();
401 f1[1] = frc.y();
402 f1[2] = frc.z();
403
404 t1[0] = trq1.x();
405 t1[1] = trq1.y();
406 t1[2] = trq1.z();
407
408 t2[0] = trq2.x();
409 t2[1] = trq2.y();
410 t2[2] = trq2.z();
411
412 return;
413 }
414 }
415
416 extern "C" {
417
418 #define fortranGetGayBerneCut FC_FUNC(getgaybernecut, GETGAYBERNECUT)
419 #define fortranDoGBPair FC_FUNC(do_gb_pair, DO_GB_PAIR)
420
421 RealType fortranGetGayBerneCut(int* atid) {
422 return OpenMD::GB::Instance()->getGayBerneCut(*atid);
423 }
424
425 void fortranDoGBPair(int *atid1, int *atid2, RealType *d, RealType *r,
426 RealType *r2, RealType *sw, RealType *vdwMult,
427 RealType *vpair, RealType *pot, RealType *A1,
428 RealType *A2, RealType *f1, RealType *t1, RealType *t2){
429
430 return OpenMD::GB::Instance()->do_gb_pair(atid1, atid2, d, r, r2, sw,
431 vdwMult, vpair, pot, A1, A2, f1,
432 t1, t2);
433 }
434 }

Properties

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svn:eol-style native