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root/OpenMD/branches/development/src/nonbonded/SHAPES.cpp
Revision: 1502
Committed: Sat Oct 2 19:53:32 2010 UTC (14 years, 7 months ago) by gezelter
File size: 16201 byte(s)
Log Message:
Many changes, and we're not quite done with this phase yet.

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
54 SHAPES::SHAPES() {
55 initialized_ = false;
56 lMax_ = 64;
57 mMax_ = 64;
58 forceField_ = NULL;
59 }
60
61 void SHAPES::initialize() {
62
63 ForceFieldOptions& fopts = forceField_->getForceFieldOptions();
64 ForceField::AtomTypeContainer* atomTypes = forceField_->getAtomTypes();
65 ForceField::AtomTypeContainer::MapTypeIterator i;
66 AtomType* at;
67
68 // SHAPES handles all of the SHAPES-SHAPES interactions as well as
69 // SHAPES-LJ cross interactions:
70
71 for (at = atomTypes->beginType(i); at != NULL;
72 at = atomTypes->nextType(i)) {
73
74 if (at->isShape() || at->isLennardJones())
75 addType(at);
76 }
77
78 initialized_ = true;
79 }
80
81 void SHAPES::addType(AtomType* atomType){
82 // add it to the map:
83 AtomTypeProperties atp = atomType->getATP();
84
85 pair<map<int,AtomType*>::iterator,bool> ret;
86 ret = ShapesMap.insert( pair<int, AtomType*>(atp.ident, atomType) );
87 if (ret.second == false) {
88 sprintf( painCave.errMsg,
89 "SHAPES already had a previous entry with ident %d\n",
90 atp.ident);
91 painCave.severity = OPENMD_INFO;
92 painCave.isFatal = 0;
93 simError();
94 }
95
96 if (atomType->isShape()) {
97 ShapeAtomType* sAtomType = dynamic_cast<ShapeAtomType*>(atomType);
98 if (sAtomType == NULL) {
99 sprintf(painCave.errMsg,
100 "SHAPES:: Can't cast to ShapeAtomType");
101 painCave.severity = OPENMD_ERROR;
102 painCave.isFatal = 1;
103 simError();
104 }
105 ShapesMap.insert( pair<int, ShapeAtomType*>(atp.ident, sAtomType) );
106
107 } else if (atomType->isLennardJones()) {
108 d1 = getLJSigma(atomType) / sqrt(2.0);
109 e1 = getLJEpsilon(atomType);
110 } else {
111 sprintf( painCave.errMsg,
112 "SHAPES::addType was passed an atomType (%s) that does not\n"
113 "\tappear to be a SHAPES or Lennard-Jones atom.\n",
114 atomType->getName().c_str());
115 painCave.severity = OPENMD_ERROR;
116 painCave.isFatal = 1;
117 simError();
118 }
119
120
121 // Now, iterate over all known types and add to the mixing map:
122
123 map<int, AtomType*>::iterator it;
124 for( it = ShapesMap.begin(); it != SHAPESMap.end(); ++it) {
125
126 AtomType* atype2 = (*it).second;
127
128 RealType d2, l2, e2, er2, dw2;
129
130 if (atype2->isGayBerne()) {
131 GayBerneParam gb2 = getGayBerneParam(atype2);
132 d2 = gb2.SHAPES_d;
133 l2 = gb2.SHAPES_l;
134 e2 = gb2.SHAPES_eps;
135 er2 = gb2.SHAPES_eps_ratio;
136 dw2 = gb2.SHAPES_dw;
137 } else if (atype2->isLennardJones()) {
138 d2 = getLJSigma(atype2) / sqrt(2.0);
139 e2 = getLJEpsilon(atype2);
140 l2 = d2;
141 er2 = 1.0;
142 dw2 = 1.0;
143 }
144
145 SHAPESInteractionData mixer;
146
147 // Cleaver paper uses sqrt of squares to get sigma0 for
148 // mixed interactions.
149
150 mixer.sigma0 = sqrt(d1*d1 + d2*d2);
151 mixer.xa2 = (l1*l1 - d1*d1)/(l1*l1 + d2*d2);
152 mixer.xai2 = (l2*l2 - d2*d2)/(l2*l2 + d1*d1);
153 mixer.x2 = (l1*l1 - d1*d1) * (l2*l2 - d2*d2) /
154 ((l2*l2 + d1*d1) * (l1*l1 + d2*d2));
155
156 // assumed LB mixing rules for now:
157
158 mixer.dw = 0.5 * (dw1 + dw2);
159 mixer.eps0 = sqrt(e1 * e2);
160
161 RealType er = sqrt(er1 * er2);
162 RealType ermu = pow(er,(1.0 / mu_));
163 RealType xp = (1.0 - ermu) / (1.0 + ermu);
164 RealType ap2 = 1.0 / (1.0 + ermu);
165
166 mixer.xp2 = xp * xp;
167 mixer.xpap2 = xp * ap2;
168 mixer.xpapi2 = xp / ap2;
169
170 // only add this pairing if at least one of the atoms is a Gay-Berne atom
171
172 if (atomType->isGayBerne() || atype2->isGayBerne()) {
173
174 pair<AtomType*, AtomType*> key1, key2;
175 key1 = make_pair(atomType, atype2);
176 key2 = make_pair(atype2, atomType);
177
178 MixingMap[key1] = mixer;
179 if (key2 != key1) {
180 MixingMap[key2] = mixer;
181 }
182 }
183 }
184 }
185
186
187 LJParam SHAPES::getLJParam(AtomType* atomType) {
188
189 // Do sanity checking on the AtomType we were passed before
190 // building any data structures:
191 if (!atomType->isLennardJones()) {
192 sprintf( painCave.errMsg,
193 "SHAPES::getLJParam was passed an atomType (%s) that does not\n"
194 "\tappear to be a Lennard-Jones atom.\n",
195 atomType->getName().c_str());
196 painCave.severity = OPENMD_ERROR;
197 painCave.isFatal = 1;
198 simError();
199 }
200
201 GenericData* data = atomType->getPropertyByName("LennardJones");
202 if (data == NULL) {
203 sprintf( painCave.errMsg, "SHAPES::getLJParam could not find Lennard-Jones\n"
204 "\tparameters for atomType %s.\n", atomType->getName().c_str());
205 painCave.severity = OPENMD_ERROR;
206 painCave.isFatal = 1;
207 simError();
208 }
209
210 LJParamGenericData* ljData = dynamic_cast<LJParamGenericData*>(data);
211 if (ljData == NULL) {
212 sprintf( painCave.errMsg,
213 "SHAPES::getLJParam could not convert GenericData to LJParam for\n"
214 "\tatom type %s\n", atomType->getName().c_str());
215 painCave.severity = OPENMD_ERROR;
216 painCave.isFatal = 1;
217 simError();
218 }
219
220 return ljData->getData();
221 }
222
223 RealType SHAPES::getLJEpsilon(AtomType* atomType) {
224 LJParam ljParam = getLJParam(atomType);
225 return ljParam.epsilon;
226 }
227 RealType SHAPES::getLJSigma(AtomType* atomType) {
228 LJParam ljParam = getLJParam(atomType);
229 return ljParam.sigma;
230 }
231
232 RealType SHAPES::getGayBerneCut(int atid) {
233 if (!initialized_) initialize();
234 std::map<int, AtomType*> :: const_iterator it;
235 it = SHAPESMap.find(atid);
236 if (it == SHAPESMap.end()) {
237 sprintf( painCave.errMsg,
238 "SHAPES::getGayBerneCut could not find atid %d in SHAPESMap\n",
239 (atid));
240 painCave.severity = OPENMD_ERROR;
241 painCave.isFatal = 1;
242 simError();
243 }
244
245 AtomType* atype = it->second;
246
247 RealType gbCut;
248
249 if (atype->isGayBerne()) {
250 GayBerneParam gb = getGayBerneParam(atype);
251
252 // sigma is actually sqrt(2) * l for prolate ellipsoids
253 gbCut = 2.5 * sqrt(2.0) * max(gb.SHAPES_l, gb.SHAPES_d);
254
255 } else if (atype->isLennardJones()) {
256 gbCut = 2.5 * LJ::Instance()->getSigma(atype);
257 }
258
259 return gbCut;
260 }
261
262
263 void SHAPES::calcForce(AtomType* at1, AtomType* at2, Vector3d d,
264 RealType r, RealType r2, RealType sw,
265 RealType &vpair, RealType &pot,
266 RotMat3x3d A1, RotMat3x3d A2, Vector3d &f1,
267 Vector3d &t1, Vector3d &t2) {
268
269 if (!initialized_) initialize();
270
271 pair<AtomType*, AtomType*> key = make_pair(at1, at2);
272 SHAPESInteractionData mixer = MixingMap[key];
273
274 RealType r3 = r2 * r;
275 RealType r5 = r3 * r2;
276
277 Vector3d drdi = -d / r;
278 Vector3d drdui = V3Zero;
279 Vector3d drdj = d / r;
280 Vector3d drduj = V3Zero;
281
282 bool i_is_LJ = at1->isLennardJones();
283 bool j_is_LJ = at2->isLennardJones();
284
285 RealType sigma_i;
286 RealType s_i;
287 RealType eps_i;
288 Vector3d dsigmaidr;
289 Vector3d disgmaidu;
290 Vector3d dsidr;
291 Vector3d dsidu;
292 Vector3d depsidr;
293 Vector3d depsidu;
294
295 if (i_is_LJ) {
296 sigma_i = LJ::Instance()->getSigma(at1);
297 s_i = sigma_i;
298 epsilon_i = LJ::Instance()->getEpsilon(at1);
299 dsigmaidr = V3Zero;
300 dsigmaidu = V3Zero;
301 dsidr = V3Zero;
302 dsidu = V3Zero;
303 depsidr = V3Zero;
304 depsidu = V3Zero;
305 } else {
306
307 // rotate the inter-particle separation into the two different
308 // body-fixed coordinate systems:
309
310 Vector3d ri = A1 * d;
311
312 RealType xi = ri.x() / r;
313 RealType yi = ri.y() / r;
314 RealType zi = ri.z() / r;
315 RealType xi2 = xi * xi;
316 RealType yi2 = yi * yi;
317 RealType zi2 = zi * zi;
318 RealType cti = zi / r;
319
320 if (cti > 1.0) cti = 1.0;
321 if (cti < -1.0_dp) cti = -1.0;
322
323 Vector3d dctidr(-zi * xi / r3,
324 -zi * yi / r3,
325 1.0 / r - zi2 / r3);
326
327 Vector3d dctidu(yi / r,
328 -zi / r,
329 0.0);
330
331 // this is an attempt to try to truncate the singularity when
332 // sin(theta) is near 0.0:
333
334 RealType sti2 = 1.0 - cti*cti;
335 if (fabs(sti2) < 1.0e-12) {
336 RealType proji = sqrt(r * 1.0e-12);
337 Vector3d dcpidx(1.0 / proji,
338 0.0,
339
340 dcpidx = 1.0_dp / proji
341 dcpidy = 0.0_dp
342 dcpidux = xi / proji
343 dcpiduy = 0.0_dp
344 dspidx = 0.0_dp
345 dspidy = 1.0_dp / proji
346 dspidux = 0.0_dp
347 dspiduy = yi / proji
348 else
349 proji = sqrt(xi2 + yi2)
350 proji3 = proji*proji*proji
351 dcpidx = 1.0_dp / proji - xi2 / proji3
352 dcpidy = - xi * yi / proji3
353 dcpidux = xi / proji - (xi2 * xi) / proji3
354 dcpiduy = - (xi * yi2) / proji3
355 dspidx = - xi * yi / proji3
356 dspidy = 1.0_dp / proji - yi2 / proji3
357 dspidux = - (yi * xi2) / proji3
358 dspiduy = yi / proji - (yi2 * yi) / proji3
359 endif
360
361 cpi = xi / proji
362 dcpidz = 0.0_dp
363 dcpiduz = 0.0_dp
364
365 spi = yi / proji
366 dspidz = 0.0_dp
367 dspiduz = 0.0_dp
368
369
370
371
372 RealType sigma0 = mixer.sigma0;
373 RealType dw = mixer.dw;
374 RealType eps0 = mixer.eps0;
375 RealType x2 = mixer.x2;
376 RealType xa2 = mixer.xa2;
377 RealType xai2 = mixer.xai2;
378 RealType xp2 = mixer.xp2;
379 RealType xpap2 = mixer.xpap2;
380 RealType xpapi2 = mixer.xpapi2;
381
382 Vector3d ul1 = A1.getRow(2);
383 Vector3d ul2 = A2.getRow(2);
384
385 RealType a, b, g;
386
387
388 if (i_is_LJ) {
389 a = 0.0;
390 ul1 = V3Zero;
391 } else {
392 a = dot(d, ul1);
393 }
394
395 if (j_is_LJ) {
396 b = 0.0;
397 ul2 = V3Zero;
398 } else {
399 b = dot(d, ul2);
400 }
401
402 if (i_is_LJ || j_is_LJ)
403 g = 0.0;
404 else
405 g = dot(ul1, ul2);
406
407 RealType au = a / r;
408 RealType bu = b / r;
409
410 RealType au2 = au * au;
411 RealType bu2 = bu * bu;
412 RealType g2 = g * g;
413
414 RealType H = (xa2 * au2 + xai2 * bu2 - 2.0*x2*au*bu*g) / (1.0 - x2*g2);
415 RealType Hp = (xpap2*au2 + xpapi2*bu2 - 2.0*xp2*au*bu*g) / (1.0 - xp2*g2);
416
417 RealType sigma = sigma0 / sqrt(1.0 - H);
418 RealType e1 = 1.0 / sqrt(1.0 - x2*g2);
419 RealType e2 = 1.0 - Hp;
420 RealType eps = eps0 * pow(e1,nu_) * pow(e2,mu_);
421 RealType BigR = dw*sigma0 / (r - sigma + dw*sigma0);
422
423 RealType R3 = BigR*BigR*BigR;
424 RealType R6 = R3*R3;
425 RealType R7 = R6 * BigR;
426 RealType R12 = R6*R6;
427 RealType R13 = R6*R7;
428
429 RealType U = vdwMult * 4.0 * eps * (R12 - R6);
430
431 RealType s3 = sigma*sigma*sigma;
432 RealType s03 = sigma0*sigma0*sigma0;
433
434 RealType pref1 = - vdwMult * 8.0 * eps * mu_ * (R12 - R6) / (e2 * r);
435
436 RealType pref2 = vdwMult * 8.0 * eps * s3 * (6.0*R13 - 3.0*R7) /(dw*r*s03);
437
438 RealType dUdr = - (pref1 * Hp + pref2 * (sigma0*sigma0*r/s3 + H));
439
440 RealType dUda = pref1 * (xpap2*au - xp2*bu*g) / (1.0 - xp2 * g2)
441 + pref2 * (xa2 * au - x2 *bu*g) / (1.0 - x2 * g2);
442
443 RealType dUdb = pref1 * (xpapi2*bu - xp2*au*g) / (1.0 - xp2 * g2)
444 + pref2 * (xai2 * bu - x2 *au*g) / (1.0 - x2 * g2);
445
446 RealType dUdg = 4.0 * eps * nu_ * (R12 - R6) * x2 * g / (1.0 - x2*g2)
447 + 8.0 * eps * mu_ * (R12 - R6) * (xp2*au*bu - Hp*xp2*g) /
448 (1.0 - xp2 * g2) / e2 + 8.0 * eps * s3 * (3.0 * R7 - 6.0 * R13) *
449 (x2 * au * bu - H * x2 * g) / (1.0 - x2 * g2) / (dw * s03);
450
451
452 Vector3d rhat = d / r;
453 Vector3d rxu1 = cross(d, ul1);
454 Vector3d rxu2 = cross(d, ul2);
455 Vector3d uxu = cross(ul1, ul2);
456
457 pot += U*sw;
458 f1 += dUdr * rhat + dUda * ul1 + dUdb * ul2;
459 t1 += dUda * rxu1 - dUdg * uxu;
460 t2 += dUdb * rxu2 - dUdg * uxu;
461 vpair += U*sw;
462
463 return;
464
465 }
466
467 void SHAPES::do_gb_pair(int *atid1, int *atid2, RealType *d, RealType *r,
468 RealType *r2, RealType *sw, RealType *vdwMult,
469 RealType *vpair, RealType *pot, RealType *A1,
470 RealType *A2, RealType *f1, RealType *t1, RealType *t2) {
471
472 if (!initialized_) initialize();
473
474 AtomType* atype1 = SHAPESMap[*atid1];
475 AtomType* atype2 = SHAPESMap[*atid2];
476
477 Vector3d disp(d);
478 Vector3d frc(f1);
479 Vector3d trq1(t1);
480 Vector3d trq2(t2);
481 RotMat3x3d Ai(A1);
482 RotMat3x3d Aj(A2);
483
484 // Fortran has the opposite matrix ordering from c++, so we'll use
485 // transpose here. When we finish the conversion to C++, this wrapper
486 // will disappear, as will the transpose below:
487
488 calcForce(atype1, atype2, disp, *r, *r2, *sw, *vdwMult, *vpair, *pot,
489 Ai, Aj, frc, trq1, trq1);
490
491 f1[0] = frc.x();
492 f1[1] = frc.y();
493 f1[2] = frc.z();
494
495 t1[0] = trq1.x();
496 t1[1] = trq1.y();
497 t1[2] = trq1.z();
498
499 t2[0] = trq2.x();
500 t2[1] = trq2.y();
501 t2[2] = trq2.z();
502
503 return;
504 }
505 }
506
507 extern "C" {
508
509 #define fortranGetGayBerneCut FC_FUNC(getgaybernecut, GETGAYBERNECUT)
510 #define fortranDoSHAPESPair FC_FUNC(do_gb_pair, DO_SHAPES_PAIR)
511
512 RealType fortranGetGayBerneCut(int* atid) {
513 return OpenMD::SHAPES::Instance()->getGayBerneCut(*atid);
514 }
515
516 void fortranDoSHAPESPair(int *atid1, int *atid2, RealType *d, RealType *r,
517 RealType *r2, RealType *sw, RealType *vdwMult,
518 RealType *vpair, RealType *pot, RealType *A1,
519 RealType *A2, RealType *f1, RealType *t1, RealType *t2){
520
521 return OpenMD::SHAPES::Instance()->do_gb_pair(atid1, atid2, d, r, r2, sw,
522 vdwMult, vpair, pot, A1, A2, f1,
523 t1, t2);
524 }
525 }

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