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root/OpenMD/branches/development/src/nonbonded/SHAPES.cpp
Revision: 1501
Committed: Wed Sep 15 19:32:10 2010 UTC (14 years, 7 months ago) by gezelter
File size: 14995 byte(s)
Log Message:
Starting migration of Morse 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/SHAPES.hpp"
47 #include "nonbonded/LJ.hpp"
48 #include "utils/simError.h"
49
50 using namespace std;
51 namespace OpenMD {
52
53 bool SHAPES::initialized_ = false;
54 int SHAPES::lMax_ = 64;
55 int SHAPES::mMax_ = 64;
56 ForceField* SHAPES::forceField_ = NULL;
57 map<int, AtomType*> SHAPES::ShapesMap;
58 map<pair<AtomType*, AtomType*>, SHAPESInteractionData> SHAPES::MixingMap;
59
60 SHAPES* SHAPES::_instance = NULL;
61
62 SHAPES* SHAPES::Instance() {
63 if (!_instance) {
64 _instance = new SHAPES();
65 }
66 return _instance;
67 }
68
69 void SHAPES::initialize() {
70
71 ForceFieldOptions& fopts = forceField_->getForceFieldOptions();
72 ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes();
73 ForceField::AtomTypeContainer::MapTypeIterator i;
74 AtomType* at;
75
76 // SHAPES handles all of the SHAPES-SHAPES interactions as well as
77 // SHAPES-LJ cross interactions:
78
79 for (at = atomTypes->beginType(i); at != NULL;
80 at = atomTypes->nextType(i)) {
81
82 if (at->isShape() || at->isLennardJones())
83 addType(at);
84 }
85
86 initialized_ = true;
87 }
88
89 void SHAPES::addType(AtomType* atomType){
90 // add it to the map:
91 AtomTypeProperties atp = atomType->getATP();
92
93 pair<map<int,AtomType*>::iterator,bool> ret;
94 ret = ShapesMap.insert( pair<int, AtomType*>(atp.ident, atomType) );
95 if (ret.second == false) {
96 sprintf( painCave.errMsg,
97 "SHAPES already had a previous entry with ident %d\n",
98 atp.ident);
99 painCave.severity = OPENMD_INFO;
100 painCave.isFatal = 0;
101 simError();
102 }
103
104 if (atomType->isShape()) {
105 ShapeAtomType* sAtomType = dynamic_cast<ShapeAtomType*>(atomType);
106 if (sAtomType == NULL) {
107 sprintf(painCave.errMsg,
108 "SHAPES:: Can't cast to ShapeAtomType");
109 painCave.severity = OPENMD_ERROR;
110 painCave.isFatal = 1;
111 simError();
112 }
113 ShapesMap.insert( pair<int, ShapeAtomType*>(atp.ident, sAtomType) );
114
115 } else if (atomType->isLennardJones()) {
116 d1 = LJ::Instance()->getSigma(atomType) / sqrt(2.0);
117 e1 = LJ::Instance()->getEpsilon(atomType);
118 } else {
119 sprintf( painCave.errMsg,
120 "SHAPES::addType was passed an atomType (%s) that does not\n"
121 "\tappear to be a Gay-Berne or Lennard-Jones atom.\n",
122 atomType->getName().c_str());
123 painCave.severity = OPENMD_ERROR;
124 painCave.isFatal = 1;
125 simError();
126 }
127
128
129 // Now, iterate over all known types and add to the mixing map:
130
131 map<int, AtomType*>::iterator it;
132 for( it = ShapesMap.begin(); it != SHAPESMap.end(); ++it) {
133
134 AtomType* atype2 = (*it).second;
135
136 RealType d2, l2, e2, er2, dw2;
137
138 if (atype2->isGayBerne()) {
139 GayBerneParam gb2 = getGayBerneParam(atype2);
140 d2 = gb2.SHAPES_d;
141 l2 = gb2.SHAPES_l;
142 e2 = gb2.SHAPES_eps;
143 er2 = gb2.SHAPES_eps_ratio;
144 dw2 = gb2.SHAPES_dw;
145 } else if (atype2->isLennardJones()) {
146 d2 = LJ::Instance()->getSigma(atype2) / sqrt(2.0);
147 e2 = LJ::Instance()->getEpsilon(atype2);
148 l2 = d2;
149 er2 = 1.0;
150 dw2 = 1.0;
151 }
152
153 SHAPESInteractionData mixer;
154
155 // Cleaver paper uses sqrt of squares to get sigma0 for
156 // mixed interactions.
157
158 mixer.sigma0 = sqrt(d1*d1 + d2*d2);
159 mixer.xa2 = (l1*l1 - d1*d1)/(l1*l1 + d2*d2);
160 mixer.xai2 = (l2*l2 - d2*d2)/(l2*l2 + d1*d1);
161 mixer.x2 = (l1*l1 - d1*d1) * (l2*l2 - d2*d2) /
162 ((l2*l2 + d1*d1) * (l1*l1 + d2*d2));
163
164 // assumed LB mixing rules for now:
165
166 mixer.dw = 0.5 * (dw1 + dw2);
167 mixer.eps0 = sqrt(e1 * e2);
168
169 RealType er = sqrt(er1 * er2);
170 RealType ermu = pow(er,(1.0 / mu_));
171 RealType xp = (1.0 - ermu) / (1.0 + ermu);
172 RealType ap2 = 1.0 / (1.0 + ermu);
173
174 mixer.xp2 = xp * xp;
175 mixer.xpap2 = xp * ap2;
176 mixer.xpapi2 = xp / ap2;
177
178 // only add this pairing if at least one of the atoms is a Gay-Berne atom
179
180 if (atomType->isGayBerne() || atype2->isGayBerne()) {
181
182 pair<AtomType*, AtomType*> key1, key2;
183 key1 = make_pair(atomType, atype2);
184 key2 = make_pair(atype2, atomType);
185
186 MixingMap[key1] = mixer;
187 if (key2 != key1) {
188 MixingMap[key2] = mixer;
189 }
190 }
191 }
192 }
193
194
195 RealType SHAPES::getGayBerneCut(int atid) {
196 if (!initialized_) initialize();
197 std::map<int, AtomType*> :: const_iterator it;
198 it = SHAPESMap.find(atid);
199 if (it == SHAPESMap.end()) {
200 sprintf( painCave.errMsg,
201 "SHAPES::getGayBerneCut could not find atid %d in SHAPESMap\n",
202 (atid));
203 painCave.severity = OPENMD_ERROR;
204 painCave.isFatal = 1;
205 simError();
206 }
207
208 AtomType* atype = it->second;
209
210 RealType gbCut;
211
212 if (atype->isGayBerne()) {
213 GayBerneParam gb = getGayBerneParam(atype);
214
215 // sigma is actually sqrt(2) * l for prolate ellipsoids
216 gbCut = 2.5 * sqrt(2.0) * max(gb.SHAPES_l, gb.SHAPES_d);
217
218 } else if (atype->isLennardJones()) {
219 gbCut = 2.5 * LJ::Instance()->getSigma(atype);
220 }
221
222 return gbCut;
223 }
224
225
226 void SHAPES::calcForce(AtomType* at1, AtomType* at2, Vector3d d,
227 RealType r, RealType r2, RealType sw,
228 RealType &vpair, RealType &pot,
229 RotMat3x3d A1, RotMat3x3d A2, Vector3d &f1,
230 Vector3d &t1, Vector3d &t2) {
231
232 if (!initialized_) initialize();
233
234 pair<AtomType*, AtomType*> key = make_pair(at1, at2);
235 SHAPESInteractionData mixer = MixingMap[key];
236
237 RealType r3 = r2 * r;
238 RealType r5 = r3 * r2;
239
240 Vector3d drdi = -d / r;
241 Vector3d drdui = V3Zero;
242 Vector3d drdj = d / r;
243 Vector3d drduj = V3Zero;
244
245 bool i_is_LJ = at1->isLennardJones();
246 bool j_is_LJ = at2->isLennardJones();
247
248 RealType sigma_i;
249 RealType s_i;
250 RealType eps_i;
251 Vector3d dsigmaidr;
252 Vector3d disgmaidu;
253 Vector3d dsidr;
254 Vector3d dsidu;
255 Vector3d depsidr;
256 Vector3d depsidu;
257
258 if (i_is_LJ) {
259 sigma_i = LJ::Instance()->getSigma(at1);
260 s_i = sigma_i;
261 epsilon_i = LJ::Instance()->getEpsilon(at1);
262 dsigmaidr = V3Zero;
263 dsigmaidu = V3Zero;
264 dsidr = V3Zero;
265 dsidu = V3Zero;
266 depsidr = V3Zero;
267 depsidu = V3Zero;
268 } else {
269
270 // rotate the inter-particle separation into the two different
271 // body-fixed coordinate systems:
272
273 Vector3d ri = A1 * d;
274
275 RealType xi = ri.x() / r;
276 RealType yi = ri.y() / r;
277 RealType zi = ri.z() / r;
278 RealType xi2 = xi * xi;
279 RealType yi2 = yi * yi;
280 RealType zi2 = zi * zi;
281 RealType cti = zi / r;
282
283 if (cti > 1.0) cti = 1.0;
284 if (cti < -1.0_dp) cti = -1.0;
285
286 Vector3d dctidr(-zi * xi / r3,
287 -zi * yi / r3,
288 1.0 / r - zi2 / r3);
289
290 Vector3d dctidu(yi / r,
291 -zi / r,
292 0.0);
293
294 // this is an attempt to try to truncate the singularity when
295 // sin(theta) is near 0.0:
296
297 RealType sti2 = 1.0 - cti*cti;
298 if (fabs(sti2) < 1.0e-12) {
299 RealType proji = sqrt(r * 1.0e-12);
300 Vector3d dcpidx(1.0 / proji,
301 0.0,
302
303 dcpidx = 1.0_dp / proji
304 dcpidy = 0.0_dp
305 dcpidux = xi / proji
306 dcpiduy = 0.0_dp
307 dspidx = 0.0_dp
308 dspidy = 1.0_dp / proji
309 dspidux = 0.0_dp
310 dspiduy = yi / proji
311 else
312 proji = sqrt(xi2 + yi2)
313 proji3 = proji*proji*proji
314 dcpidx = 1.0_dp / proji - xi2 / proji3
315 dcpidy = - xi * yi / proji3
316 dcpidux = xi / proji - (xi2 * xi) / proji3
317 dcpiduy = - (xi * yi2) / proji3
318 dspidx = - xi * yi / proji3
319 dspidy = 1.0_dp / proji - yi2 / proji3
320 dspidux = - (yi * xi2) / proji3
321 dspiduy = yi / proji - (yi2 * yi) / proji3
322 endif
323
324 cpi = xi / proji
325 dcpidz = 0.0_dp
326 dcpiduz = 0.0_dp
327
328 spi = yi / proji
329 dspidz = 0.0_dp
330 dspiduz = 0.0_dp
331
332
333
334
335 RealType sigma0 = mixer.sigma0;
336 RealType dw = mixer.dw;
337 RealType eps0 = mixer.eps0;
338 RealType x2 = mixer.x2;
339 RealType xa2 = mixer.xa2;
340 RealType xai2 = mixer.xai2;
341 RealType xp2 = mixer.xp2;
342 RealType xpap2 = mixer.xpap2;
343 RealType xpapi2 = mixer.xpapi2;
344
345 Vector3d ul1 = A1.getRow(2);
346 Vector3d ul2 = A2.getRow(2);
347
348 RealType a, b, g;
349
350
351 if (i_is_LJ) {
352 a = 0.0;
353 ul1 = V3Zero;
354 } else {
355 a = dot(d, ul1);
356 }
357
358 if (j_is_LJ) {
359 b = 0.0;
360 ul2 = V3Zero;
361 } else {
362 b = dot(d, ul2);
363 }
364
365 if (i_is_LJ || j_is_LJ)
366 g = 0.0;
367 else
368 g = dot(ul1, ul2);
369
370 RealType au = a / r;
371 RealType bu = b / r;
372
373 RealType au2 = au * au;
374 RealType bu2 = bu * bu;
375 RealType g2 = g * g;
376
377 RealType H = (xa2 * au2 + xai2 * bu2 - 2.0*x2*au*bu*g) / (1.0 - x2*g2);
378 RealType Hp = (xpap2*au2 + xpapi2*bu2 - 2.0*xp2*au*bu*g) / (1.0 - xp2*g2);
379
380 RealType sigma = sigma0 / sqrt(1.0 - H);
381 RealType e1 = 1.0 / sqrt(1.0 - x2*g2);
382 RealType e2 = 1.0 - Hp;
383 RealType eps = eps0 * pow(e1,nu_) * pow(e2,mu_);
384 RealType BigR = dw*sigma0 / (r - sigma + dw*sigma0);
385
386 RealType R3 = BigR*BigR*BigR;
387 RealType R6 = R3*R3;
388 RealType R7 = R6 * BigR;
389 RealType R12 = R6*R6;
390 RealType R13 = R6*R7;
391
392 RealType U = vdwMult * 4.0 * eps * (R12 - R6);
393
394 RealType s3 = sigma*sigma*sigma;
395 RealType s03 = sigma0*sigma0*sigma0;
396
397 RealType pref1 = - vdwMult * 8.0 * eps * mu_ * (R12 - R6) / (e2 * r);
398
399 RealType pref2 = vdwMult * 8.0 * eps * s3 * (6.0*R13 - 3.0*R7) /(dw*r*s03);
400
401 RealType dUdr = - (pref1 * Hp + pref2 * (sigma0*sigma0*r/s3 + H));
402
403 RealType dUda = pref1 * (xpap2*au - xp2*bu*g) / (1.0 - xp2 * g2)
404 + pref2 * (xa2 * au - x2 *bu*g) / (1.0 - x2 * g2);
405
406 RealType dUdb = pref1 * (xpapi2*bu - xp2*au*g) / (1.0 - xp2 * g2)
407 + pref2 * (xai2 * bu - x2 *au*g) / (1.0 - x2 * g2);
408
409 RealType dUdg = 4.0 * eps * nu_ * (R12 - R6) * x2 * g / (1.0 - x2*g2)
410 + 8.0 * eps * mu_ * (R12 - R6) * (xp2*au*bu - Hp*xp2*g) /
411 (1.0 - xp2 * g2) / e2 + 8.0 * eps * s3 * (3.0 * R7 - 6.0 * R13) *
412 (x2 * au * bu - H * x2 * g) / (1.0 - x2 * g2) / (dw * s03);
413
414
415 Vector3d rhat = d / r;
416 Vector3d rxu1 = cross(d, ul1);
417 Vector3d rxu2 = cross(d, ul2);
418 Vector3d uxu = cross(ul1, ul2);
419
420 pot += U*sw;
421 f1 += dUdr * rhat + dUda * ul1 + dUdb * ul2;
422 t1 += dUda * rxu1 - dUdg * uxu;
423 t2 += dUdb * rxu2 - dUdg * uxu;
424 vpair += U*sw;
425
426 return;
427
428 }
429
430 void SHAPES::do_gb_pair(int *atid1, int *atid2, RealType *d, RealType *r,
431 RealType *r2, RealType *sw, RealType *vdwMult,
432 RealType *vpair, RealType *pot, RealType *A1,
433 RealType *A2, RealType *f1, RealType *t1, RealType *t2) {
434
435 if (!initialized_) initialize();
436
437 AtomType* atype1 = SHAPESMap[*atid1];
438 AtomType* atype2 = SHAPESMap[*atid2];
439
440 Vector3d disp(d);
441 Vector3d frc(f1);
442 Vector3d trq1(t1);
443 Vector3d trq2(t2);
444 RotMat3x3d Ai(A1);
445 RotMat3x3d Aj(A2);
446
447 // Fortran has the opposite matrix ordering from c++, so we'll use
448 // transpose here. When we finish the conversion to C++, this wrapper
449 // will disappear, as will the transpose below:
450
451 calcForce(atype1, atype2, disp, *r, *r2, *sw, *vdwMult, *vpair, *pot,
452 Ai, Aj, frc, trq1, trq1);
453
454 f1[0] = frc.x();
455 f1[1] = frc.y();
456 f1[2] = frc.z();
457
458 t1[0] = trq1.x();
459 t1[1] = trq1.y();
460 t1[2] = trq1.z();
461
462 t2[0] = trq2.x();
463 t2[1] = trq2.y();
464 t2[2] = trq2.z();
465
466 return;
467 }
468 }
469
470 extern "C" {
471
472 #define fortranGetGayBerneCut FC_FUNC(getgaybernecut, GETGAYBERNECUT)
473 #define fortranDoSHAPESPair FC_FUNC(do_gb_pair, DO_SHAPES_PAIR)
474
475 RealType fortranGetGayBerneCut(int* atid) {
476 return OpenMD::SHAPES::Instance()->getGayBerneCut(*atid);
477 }
478
479 void fortranDoSHAPESPair(int *atid1, int *atid2, RealType *d, RealType *r,
480 RealType *r2, RealType *sw, RealType *vdwMult,
481 RealType *vpair, RealType *pot, RealType *A1,
482 RealType *A2, RealType *f1, RealType *t1, RealType *t2){
483
484 return OpenMD::SHAPES::Instance()->do_gb_pair(atid1, atid2, d, r, r2, sw,
485 vdwMult, vpair, pot, A1, A2, f1,
486 t1, t2);
487 }
488 }

Properties

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